1. Thermal phenomena
1 What motion is called thermal? The random movement of the particles that make up bodies is called thermal motion.
2 What energy is called the internal energy of a body? The kinetic energy of the molecules that make up the body and the potential energy of their interaction constitute the internal energy of the body.
3 In what ways can internal energy be changed? The internal energy of a body can be changed in two ways: by performing mechanical work and by heat transfer.
4 What is heat transfer? The process of changing internal energy without doing work on the body or the body itself is called heat transfer.
5 In what ways can heat transfer be carried out? Heat transfer can be accomplished in three ways: conduction, convection and radiation.
6 What phenomenon is called thermal conductivity? The phenomenon of transfer of internal energy from one body to another or from one part to another is called thermal conductivity.
7 What phenomenon is called convection? The phenomenon of energy transfer by its transfer by the jets of gas or liquid themselves is called convection.
8 What properties do bodies under the influence of radiation have? Bodies have the ability to absorb radiation energy.
9 What is the amount of heat? The energy that a body gains or loses during heat transfer is called the amount of heat.
10 What determines the amount of heat needed to heat a body? The amount of heat that is necessary to heat a body depends on the mass of this body, on changes in its temperature and the type of substance.
11 What is called specific heat capacity substances? A physical quantity numerically equal to the amount of heat that must be transferred to a body weighing 1 kg in order for its temperature to change by 1 degree Celsius is called the specific heat capacity of a substance.
12 In what SI units is the amount of heat measured? The amount of heat in the international system is measured in joules (J).
13 What is the specific heat of combustion of fuel? A physical quantity showing how much heat is released during the complete combustion of fuel weighing 1 kg is called the specific heat of combustion of the fuel.
14 The law of conservation of energy in mechanical and thermal processes. In all phenomena occurring in nature, energy neither appears nor disappears. It only transforms from one type to another, while its meaning remains the same.
15 What are the SI units of specific heat capacity of a substance? The SI unit of measurement for the specific heat capacity of a substance is J/(kg* 0C)
16 What are the SI units of specific heat of combustion of fuel? The SI unit of measurement for the specific heat of combustion of fuel is J/kg.
2. Change in aggregative states of matter
17 Which ones states of aggregation could it be the same substance? The same substance can be in three states of aggregation: solid, liquid and gaseous.
18 Do molecules of the same substance in solid, liquid and gaseous states differ from each other? molecules of the same substance in solid, liquid and gaseous states are no different from each other.
19 What process is called melting? The transition of a substance from a solid to a liquid state is called melting.
20 What process is called hardening? The transition of a substance from a liquid to a solid state is called solidification.
21 What is the temperature at which a substance melts is called? The temperature at which a substance melts is called the melting point of the substance.
22 What is the temperature at which a substance crystallizes is called? The temperature at which a substance solidifies is called the crystallization temperature of the substance.
23 Does the temperature change during the melting of a substance? During the melting process of a substance, the body temperature does not change.
24 Does the temperature change during the crystallization of a substance? During the solidification process, the body temperature does not change.
25 What is the specific heat of fusion called? A physical quantity showing how much heat must be imparted to a crystalline body weighing 1 kg in order to completely transform it into a liquid state at the melting point is called the specific heat of fusion.
26 SI unit of measurement of specific heat of fusion. In the international system, the specific heat of fusion is measured in J/kg.
27 What process is called vaporization? The phenomenon of turning a liquid into vapor is called vaporization.
28 What process is called evaporation? Vapor formation occurring from the surface of a liquid is called evaporation.
29 Which steam is called saturated? Vapor that is in dynamic equilibrium with its liquid is called saturated vapor.
30 Which steam is called unsaturated? Vapor that is not in dynamic equilibrium with its liquid is called unsaturated.
31 What phenomenon is called condensation? The phenomenon of vapor turning into liquid is called condensation.
32 What phenomenon is called boiling? Boiling is an intensive transition of liquid into vapor, which occurs with the formation of vapor bubbles throughout the entire volume of the liquid at a certain temperature.
33 What is the boiling point of a liquid called? The temperature at which a liquid boils is called the boiling point.
34 What is relative humidity? Relative air humidity is the ratio of absolute air humidity to the density of saturated water vapor at the same temperature, expressed as a percentage.
35 What is the dew point called? The temperature at which vapor in the air becomes saturated is called the dew point.
36 What is the specific heat of vaporization called? A physical quantity showing how much heat must be imparted to a liquid weighing 1 kg at boiling point in order to completely transform it into steam is called the specific heat of vaporization
37 SI unit of measurement of the specific heat of vaporization. In the international system, the specific heat of vaporization is measured in J/kg.
38 What engines are called thermal engines? Heat engines are machines in which the internal energy of fuel is converted into mechanical energy.
39 Which engine is called an internal combustion engine (ICE)? An internal combustion engine is a heat engine in which fuel burns in the cylinder itself.
40 What is called coefficient useful action? Perfect attitude useful work engine to the energy received from the heater is called the efficiency of the heat engine.
3. Electrical phenomena
41 What two types of electric charges exist in nature? There are two types of electrical charges in nature: positive and negative.
42 How do bodies with charges of the same sign interact? Bodies with electric charges of the same sign repel each other.
43 How do bodies with charges interact? different sign? Bodies with electric charges of different signs attract each other.
44 What are conductors called? Conductors are bodies through which electric charges can pass from a charged body to an uncharged one.
45 What are called non-conductors? Nonconductors are bodies through which electric charges cannot pass from a charged body to an uncharged one.
46 What is electric field and its properties? An electric field is a special type of matter, different from matter. It arises around any stationary electric charge and spreads in any medium (even in a vacuum).
47 What force is called electric? The force with which an electric field acts on an electric charge introduced into it is called electric force.
48 What is an electron? An electron is an elementary charged particle that has the smallest charge that cannot be divided. q=1.610-19Kl.
49 What is the structure of atoms? An atom consists of a positively charged nucleus and negatively charged electrons orbiting around this nucleus.
50 What is the structure of the nucleus of an atom? The nucleus of an atom consists of electrically neutral neutrons and positively charged protons.
51 Why are bodies usually electrically neutral? The sum of all negative charges in a body is equal in absolute value to the sum of all positive charges.
52 What is electric current? Electric current is the directional movement of charged particles.
53 What needs to be created in a conductor for an electric current to arise and exist in it? To create an electric current in a conductor, you need to create an electric field in it using a current source (power supply, galvanic cell or battery).
54 What parts does an electrical circuit consist of? A current source, electric current consumers, closing devices connected to each other by wires make up a simple electrical circuit.
55 What is electric current in metals? Electric current in metals is the ordered movement of free electrons.
56 What phenomena does electric current cause? Electric current causes the following phenomena: thermal, chemical and magnetic.
57 The direction of movement of which particles in a conductor is taken to be the direction of the current? The direction of the electric current is taken to be the direction of movement of positively charged particles.
58 In what SI units is current measured? In the international system, current is measured in amperes (A).
59 What is the name of the device for measuring current and how is it connected to an electrical circuit? A device for measuring current is called an ammeter and is connected in series to an electrical circuit.
60 What is electrical voltage? Voltage is a physical quantity that characterizes the electric field created by a current source in conductors.
61 What is the name of the device for measuring voltage and how is it connected to the electrical circuit? A device for measuring voltage is called a voltmeter and is connected to an electrical circuit in parallel to the conductor on which the voltage needs to be measured.
62 What is electrical resistance? Electrical resistance is a physical quantity that depends on the properties of the conductor (length, cross-sectional area, type of substance).
63 In what SI units is resistance measured? In the international system, resistance is measured in ohms (Ohms).
64 Ohm's law for a section of a circuit. The current strength in a section of a circuit is directly proportional to the voltage at the ends of this section and inversely proportional to its resistance.
65 What is the resistivity of a conductor called? The resistance of a conductor made of a given substance with a length of 1 m and a cross-sectional area of 1 m2 is called the resistivity of the conductor.
66 Which connection in an electrical circuit is called serial? A series connection is a connection in which the end of the first conductor is connected to the beginning of the second, the end of the second conductor is connected to the beginning of the third, and so on.
67 Which connection in an electrical circuit is called parallel? A parallel connection is a connection in which the beginnings of all the conductors and, accordingly, all their ends are connected to each other.
68 In what SI units is the work of an electric current measured? The work done by electric current in the international system is measured in joules (J).
69 What is the power of electric current called? Power is a physical quantity that shows how much work the current does in a conductor per unit of time.
70 In what SI units is power measured? Power in the international system is measured in watts (W).
4. Electromagnetic phenomena
71 What is a magnetic field? A magnetic field is a special type of matter, different from matter and existing independently of our consciousness, formed only around moving electric charges.
72 What is called a magnetic line magnetic field? The lines along which the axes of small magnetic needles are located in a magnetic field are called magnetic field lines.
73 What is called an electromagnet? A coil with an iron core inside is called an electromagnet.
74 What bodies are called permanent magnets? bodies, long time retaining magnetization are called permanent magnets.
75 How do the poles of magnets interact with each other? Like poles of magnets repel, and opposite poles attract.
76 Where are the Earth's magnetic poles? The Earth's magnetic poles do not coincide with its geographic poles: where the north geographic pole is, there is a south magnetic pole; where the south geographic pole is, there is the north magnetic pole.
77 What direction do the magnetic field lines have? Magnetic field lines begin at the north magnetic pole and end at the south magnetic pole.
78 What effect does a magnetic field have on a current-carrying conductor? A magnetic field acts with some force on any current-carrying conductor located in this field.
5. Light phenomena
79 Which luminous body is called a point source? If the dimensions of a luminous body are much smaller than the distance at which we evaluate its action, then the luminous body is called a point source.
80 What is a ray of light? A light ray is a line along which energy from a light source travels.
81 What is a shadow? A shadow is that area of space that does not receive light from a source.
82 What is penumbra? Penumbra is the area of space into which light falls from part of the light source.
83 Formulate the laws of light reflection. The incident and reflected rays lie in the same plane with a perpendicular drawn to the interface between the two media at the point of incidence of the ray. Angle of incidence equal to angle reflections.
84 Formulate the laws of light refraction. The incident, refracted and perpendicular rays drawn to the interface between two media at the point of incidence of the ray lie in the same plane. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant value for two media.
85 What bodies are called lenses? They are called lenses transparent bodies, bounded on both sides by spherical surfaces.
86 What types of lenses are there? There are two types of lenses: convex (converging) and concave (diffusing).
87 Which point is called the focus of the lens? The focal point of a lens is the point at which all refracted rays incident on the lens parallel to the main optical axis intersect.
88 What is focal length called? The distance from a lens to its focus is called the focal length of the lens.
What is the optical power of a lens? The optical power of a lens is the reciprocal of its focal length.
89 What is the optical power of a lens called? The optical power of a lens is the reciprocal of its focal length.
90 What is the unit of optical power of a lens called? The unit of optical power of a lens is the diopter (dopter).
91 What images can be obtained using a lens? Real, imaginary, increased, decreased, equal, inverted, upright.
Nikolskaya Secondary School
Compiled by: physics and computer science teacher
Nikolskaya Secondary School
Spassky district
Republic of Tatarstan
Avdonina V.P.
8th grade
Physical dictations type 1.
Select from the listed concepts units of measurement, physical quantities, instruments, phenomena, processes. Present the answer in the form of a table:
units | physical quantities | devices | processes |
joule, energy, free fall, diffusion, speed, temperature, C, m/s, potential energy, deformation, internal energy;
heat transfer, calorie, thermometer, beaker, calorimeter, convection, kg, heat capacity, mass, J/kg, C, temperature, thermal conductivity, amount of heat;
melting, specific heat of fusion, specific heat of combustion of fuel, mg, scales, vaporization, amount of heat, J/kg,Q, boiling, specific heat of vaporization
humidity, psychrometer, relative humidity, hair hygrometer, C, temperature, %, evaporation, condensation;
current strength,R, ampere, milliammeter, electrical voltage, voltmeter, Ohm, rheostat, resistivity, Mmm 2 , cross-sectional area;
electric current work, joule. Watt, electric current power, wattmeter, kW h,I, A, key, resistor, electric bell, amount of heat;
electric motor, electromagnet, ammeter, rheostat, ampere, Ohm,
reflection of light, diopter, diopter, optical power, focus, light refraction, meter,D, lens, solar eclipse, shadow, 3 10 8 m/s.
physical dictations II type
Select from the listed concepts, words, phrases associated with the phenomena. Present the answer in the form of a table:
thermal and electrical phenomena
electrification, convection, heat capacity, heat transfer, current strength, electric charge, electron, charge fissibility, radiation, specific heat of fusion, heat transfer, Ioffe-Miliken experiment, Ohm's law, resistance, joule, Joule-Lenz law, specific heat of combustion of fuel, proton , neutron, E. Rutherford, electric field;
electrical and magnetic phenomena
magnetic field, pole, watt, resistivity, current power, lines of force, ampere, B. Jacobi, electromagnet, uniform field, work of electric current, 1 Ohm, A.M. Ampere, A. Volta, G. Oersted, compass, northern lights, KMA, D. Maxwell, rheostat, permanent magnet, kW, fuse, short circuit, Lodygin, pole, Edison;
magnetic and light phenomena
straightness of propagation, pole, ammeter, reflection, plane mirror, compass, refraction, lens, Oersted, focus, optical power, shadow, eclipse, iron filings, " Flying Dutchman", diopter, image, 3 10 8 m/s, focal length,D, lines of force, core, anchor, magnifying glass, scattering, microscope.
Physical dictation III type
Fill in the missing words or complete the sentence.
Subject: Internal energy.
A molecule is the smallest particle of……(substance)
There are two types of mechanical energy that atoms possess: ..... (kinetic and potential).
The energy of movement and interaction of particles that make up a body is called.... (internal energy)
Internal energy of the body... from its mechanical energy. (does not depend).
When a body's temperature rises, its internal energy... (increases).
The transfer of energy from more heated parts of the body to less heated ones due to the thermal movement of particles is called ... (thermal conductivity).
When bending and unbending an aluminum wire, its internal energy changes in the way .... (doing work on the body).
Among metals, ... (silver, gold) have the highest thermal conductivity.
Porous bodies have poor thermal conductivity because they contain... (air).
Heat transfer in a vacuum by thermal conductivity... (impossible).
In solids, convection occurs... (cannot).
The transfer of energy from the Sun to the Earth is carried out by ... (radiation).
Bodies with a dark surface...absorb the energy of radiation incident on them. (Fine)
For convection to occur in water, it must be cooled... or heated... (from above, from below).
Subject: Thermal phenomena
The energy that a body gains or loses during heat transfer is called ... (amount of heat).
The unit of heat is called... (joule).
The specific heat capacity of water is ... (4200 J/kg WITH).
The specific heat capacity of the same substance in different states of aggregation... (is different).
Melting is the transition of a substance... (from solid to liquid).
The amount of heat released during complete combustion of 1 kg of fuel is called ... (specific heat of combustion of the fuel).
At the melting temperature, the internal energy of water, ... the internal energy of the same mass of ice at 0 S. (more)
When ice melts, its temperature ... (does not change).
The crystallization process is accompanied by... heat. (emphasis added)
The formula for the amount of heat required to melt a substance... (Q= m)
Amorphous bodies include, for example... (glass, rosin, candy)
Amorphous bodies... of a certain melting point. (Dont Have)
The reverse process to vaporization is called... (condensation)
Formation of dew. Clouds are associated with such a thermal phenomenon as ... (condensation)
Condensation is accompanied by... energy. (emphasis added)
The amount of heat required to convert 1 kg of liquid at boiling point into vapor is called ... (specific heat of vaporization)
During boiling, the temperature of the liquid... (does not change)
boiling and condensation temperatures for a given substance... (same)
Subject: Electrical phenomena.
Electron is translated from Greek as ... (amber)
The process of charge separation is called ... (electrification)
There are two types of charges:... (positive and negative)
Like charges..., and unlike charges... (repel, attract)
The electric charge is divided into... parts. (equal)
One of the methods of electrification is ... (friction)
A device for measuring electric charge is called ... (electrometer)
The minimum electric charge is ... (1.6 10 -19 Cl)
Part atomic nucleus includes...(protons and neutrons)
The idea of the atomic nucleus belongs to... (E. Rutherford)
A special type of matter is formed around a charged body, which is called ... (electric field)
Electrification is used, for example... (when painting car bodies, when smoking.)
English physicists studied the interaction of electric charges: ... and ... (D. Maxwell and M. Faraday)
The unit of measurement of electric charge is named after the French physicist... (S.O. Coulomb)
Topic: Electric current. Current strength.
Topic: Electric voltage.
Voltage is a physical quantity that characterizes..., which creates a current. (electric field)
The voltage shows ... when moving an electric charge equal to 1 C. (current work)
The value equal to the ratio of the work of the current in a given area to the electric charge passing through this area is called ... (voltage)
The unit of voltage is... (volt)
The unit of voltage is named after the Italian scientist... (A. Volta)
1 V = ... (1 J/ Cl)
The lighting network uses voltage... (220 V)
To measure voltage, a device called ... (voltmeter) is used.
The voltmeter clamps are connected to those points of the circuit between which the voltage must be measured; this connection of the device is called ... (parallel)
The current in the circuit is directly proportional to ... (the voltage at the ends of the circuit)
Voltage is indicated by a letter of the Latin alphabet - ... (U)
Subject: Electrical resistance.
The current strength in the circuit depends not only on the voltage, but also on ... (properties of the conductor)
The dependence of current strength on the properties of the conductor is explained by different ... (resistance)
The unit of resistance is taken... (Ohm)
The unit of measurement of electrical resistance of a conductor is named after the German physicist ... (G. Ohm)
The reason for the resistance of the conductor is ... (the interaction of moving electrons with ions of the crystal lattice)
The current strength in a conductor is inversely proportional to ... (its resistance)
The current strength in a section of a circuit is directly proportional to the voltage at the ends of this section and inversely proportional to its resistance - this is the law ... (Ohm)
By how many times does the resistance of a conductor increase, by how many times does it decrease... with constant... (current strength in the conductor, voltage at the ends of the conductor)
Resistance of a conductor made of this substance 1 m long, cross-sectional area 1 m 2 called... (resistivity)
A device for regulating the current in a circuit is called ... (rheostat)
Topic: Parallel and series connection of conductors
A connection in which the end of one section is connected to the beginning of the next, and forms a closed circuit, is called ... (series)
An example of a series connection is the connection ... (light bulbs in a Christmas tree garland)
In a series connection, the current strength in any part of the circuit... (the same)
The total resistance of the circuit when connected in series is equal to ... (the sum of the resistances of its individual sections)
The total voltage in the circuit in a series connection, or the voltage at the poles of the current source, is equal to ... (the sum of the voltages in individual sections of the circuit)
A connection in which all the conductors included in it are connected with one end to one point, and the other end to another point is called ... (parallel)
An example of a parallel connection is the connection ... (lights and sockets in the apartment)
The voltage on a section of the circuit and at the ends of all parallel-connected conductors.... (same)
The current strength in the unbranched part of the circuit is equal to ... in individual parallel-connected conductors. (amount)
The reciprocal of resistance is called... (conductivity)
With a parallel connection, the conductivity of the entire circuit is equal to ... the conductivities of its individual sections. (amount)
Topic: Work and power of electric current.
To determine the work of electric current on any section of the circuit, it is necessary ... (the voltage at the ends of this section of the circuit is multiplied by the electric charge)
The work of an electric current on a section of a circuit is equal to ... (the product of the voltage at the ends of this section by the current strength and the time during which the work was performed)
The power of the electric current is equal to ... (the product of voltage and current)
The unit of power is taken.. (watt)
1 W = ... (1 J/ With)
To measure the power of electric current, instruments are used - ... (wattmeters)
1 kW h = ... J. (3600000 J)
Joule - Lenz law - .... (the amount of heat generated by a conductor is equal to the product of the square of the current, the resistance of the conductor and time)
A lamp convenient for industrial production with a carbon filament was created by an American inventor.... (T. Edison)
The electric incandescent lamp was created by a Russian engineer... (A.N. Lodygin)
The connection of the ends of a section of a circuit with a conductor whose resistance is very small compared to the resistance of the circuit is called ... (short circuit)
Purpose of fuses ... (immediately turn off the line if the current strength exceeds the permissible limit)
Fuses with a melting conductor are called ... (fusible)
A device for measuring the work of electric current is called ... (meter)
Subject: Magnetic phenomena.
Interaction forces arise between current-carrying conductors, which are called ... (magnetic)
The interaction of a conductor with a current and a magnetic needle was first discovered by a Danish scientist... (Ørsted)
Around the conductor with electric shock exists... (magnetic field)
The source of the magnetic field is ... (moving charge)
The magnetic field around a current-carrying conductor can be detected, for example... (using a magnetic needle, using iron filings)
The lines along which the axes of small magnetic needles are located in a magnetic field are called ... (magnetic lines of force)
magnetic field lines are...curves that enclose a conductor. (closed)
A coil with an iron core inside is called... (electromagnet)
The magnetic field of a coil with current can be strengthened if, ... (increase the current, increase the number of turns in the coil, insert a core)
Electromagnets are used, for example... (in telephones, telegraphs, magnetic relays)
Bodies that retain their magnetization for a long time are called... (permanent magnets)
Every magnet must have... (pole)
Like poles of a magnet ..., and unlike poles - ... (repel, attract)
The Earth has... (a magnetic field)
The Earth's magnetic poles... with its geographic poles. (do not match)
One of the biggest magnetic anomalies- ... (Kursk)
The compass was invented in... (China)
The rotation of a coil with current in a magnetic field is used in a device ... (electric motor)
One of the world's first electric motors suitable for practical application, was invented by a Russian scientist... (B.S. Jacobi)
Subject: Light phenomena.
Light is... (visible radiation)
Light sources are divided into ... and ... (natural and artificial)
If the dimensions of a luminous body are much smaller than the distance at which we evaluate its action, then the luminous body is called ... (point source)
A light ray is a line... (along which light propagates)
A shadow is that area of space... (in which light from the source does not enter)
Penumbra is that region of space... (in which light from part of the source enters)
When the Moon falls into the Earth's shadow, it is observed... (lunar eclipse)
When the shadow of the moon falls on the Earth, at this place on Earth there is... (solar eclipse)
The angle between the incident beam and the perpendicular reconstructed at the point of incidence of the beam to the interface between two media is called ... (angle of incidence)
The angle of incidence is equal to ... (angle of reflection)
The virtual image of an object in a plane mirror is located ... at a distance from the mirror at which the object itself is located. (on the same one)
The dimensions of the image of an object in a flat mirror... (equal)
The optical density of a medium is characterized by ... the propagation of light. (speed)
The change in the direction of light propagation at the interface between two media is called ... (refraction)
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is ... (a constant value for these two media)
Transparent bodies bounded on both sides by spherical surfaces are called... (lenses)
There are two types of lenses: ... (convex and concave)
A lens whose edges are thicker than the middle is... (concave)
A lens whose edges are much thinner than the middle is... (convex)
Each lens has two... - one on each side. (focus)
A convex lens is called ..., and a concave lens is called ... (converging, diverging)
The reciprocal of the focal length of the lens is called ... (optical power)
IfF< d<2 F, then the image will be ... (real, enlarged, inverted, located on the other side of the lens)
Ifd>2 F, then the image will be ... (real, inverted, reduced, located on the other side of the lens)
Ifd< F, then the image will be ... (imaginary, direct, enlarged, located on one side of the lens)
Lenses are used in devices, for example: ... (microscope, camera, telescope)
Physical dictation + physical education minute (for students in grades 7 and 8)
Physical quantity, its designation, unit of measurement, device, formula, term associated with physical quantity etc. corresponds to the appropriate meaning physical exercise(the exercise can be done while sitting)
force - arms are bent at the elbows, demonstrating their muscles (“strongmen”)
time - look at the hand, bending it at the elbow, imitating the movement when looking at the watch put on the hand;
speed - imitate running;
length, path - arms to the side;
height - hands up;
temperature - rubbing hands;
volume - spread their arms to the side, showing the volume of the ball;
weight - raise their arms up, simulating the movement of lifting a barbell;
density - show two exercises related to mass and volume in a row
pressure - rise on a chair on their hands
Job - do two exercises in a row related to strength and path
energy - jumping in place
Children are happy to come up with such exercises themselves.
Seven troubles, one answer. (based on the television game of the same name)
Seven signs for one:
Thermal phenomena
1.1).Physical quantity
2). Hot - cold
3).Thermal phenomena are associated with its change
4).if it increases, then the molecules move faster
5). Degree Celsius
6).If it increases with us, we are sick
7). It is measured using a thermometer
answer: temperature
2.1).thermal movement
2).molecules
3). Depends on the state of aggregation
4) deformation
5). Does not depend on the mechanical movement of the body
6). Very big
7). Can be changed in two ways
answer: internal energy
3.1).It can be bad and good for different substances
2). Vacuum
3). “Does a fur coat keep you warm?”
4). "He's ruffled like a sparrow"
5). Good for metals
6). The phenomenon of internal energy transfer
answer: thermal conductivity
4.1). Phenomenon
2). Wind
3). It can be natural and free
4). Cannot occur in solids
5). Needs to be heated from below
6). Energy is transferred by jets of gas or liquid
7). Type of heat transfer
answer: convection
5.1). Sun
2).Thermoscope
3) White and black
4). Can be carried out in complete vacuum
5). There are visible and invisible
6). We do this too
7). One type of heat transfer
answer: radiation
6.1).Energy
2). Heat transfer
3). Calorimeter
4). Depends on mass
5). Depends on body temperature difference
6). Depends on the type of substance
7). Measured in joules
7.1).One of two ways
2). Occurs at any temperature
3). The larger the surface of the liquid, the greater its speed
4). In Finnish and Russian baths it occurs at different speeds
5). Its speed depends on the type of liquid
6) It happens faster the higher the temperature
7) Liquid vapor
answer: evaporation
8.1).Bubbles
2). Archimedes' power
3). Kettle with whistle
4). One of two ways
5). Occurs at a certain temperature
6). 100 WITH
7). When this happens, the temperature of the liquid does not change
answer: boiling
9.1).Gas work
2). Fuel energy mechanical energy
3). XVII
4). James Watt
5). Dead point
6).It can be four-stroke
7). Has efficiency
answer: heat engine
Magnetic phenomena
10.1). Hans Christian Oersted
2). A special kind of matter
3). Its source is a moving charge
4). Can be detected using iron filings
5). Has power lines
6). It can be strengthened and weakened
7). The Earth has it
answer: magnetic field
11.1). North and South
2). Coil
3). Core
4). Telephone
5). Its effect can be strengthened or weakened
6). It can change the poles
7). You can easily make it yourself
answer: electromagnet
12.1). It uses the property of a magnetic field to act on a current-carrying conductor
2). Anchor
3). Stator
4). 1834
5). Boris Semenovich Jacobi
6). High efficiency
7). Widely used in transport
answer: electric motor
Light phenomena
13.1). "Sunny Bunny"
2). "Flying Dutchman"
3). Periscope
4). Reflection angle
5). Interface between two media
6). Reversibility of light rays
7). The angle of incidence is equal to the angle of reflection
answer: law of reflection of light
14.1).It occurs at the border
2). The light changes direction
3). In fact, the stars are closer to us
4). It happens according to the law
5). It can be controlled using a prism
6). Fishermen need to take this into account
7). If it does not occur, then the reflection is complete
answer: refraction
15.1). With its help you can control light beams
2). They are in our eyes
3). They are convex and concave
4). They have tricks
5). They scatter and gather
6). They are characterized by optical powerDocument
Geography for course 6 class « Physical Geography" Teachers highest category... North-Eastern America. Geographical dictation 1.Name the industries modern geography. ... long-term weather regime C) weather D) type weather 7. Thickness of the bottom layer...
Class 10 Lesson Type
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Chapter 4. ELECTROMAGNETIC PHENOMENA
This chapter is devoted to various electromagnetic phenomena. The chapter consists of paragraphs and is devoted to the analysis of these phenomena.
Sources of light. Spread of Light
Light is radiation, but only that part of it that is perceived by the eye. In this regard, light is called visible radiation.
The bodies from which light emanates are sources of light.
Light sources are divided into natural and artificial.
Natural sources Sveta- this is the Sun, stars, atmospheric discharges, as well as luminous objects of the animal and plant world.
Artificial light sources, depending on what process underlies the production of radiation, are divided into thermal and luminescent.
TO thermal include light bulbs, gas burner flames, candles, etc.
Luminescent sources are fluorescent and gas light lamps
All light sources have dimensions. When studying light phenomena, we will use the concept of a point source of light.
If the dimensions of the luminous body are much smaller than the distance at which we evaluate its action, then the luminous body can be considered a point source.
Another concept we will use in this section is a light beam.
A light ray is a line along which energy from a light source travels.
§ 64. Apparent movement of the luminaries
The sun and the celestial bodies moving around it make up the solar system. The path that the Sun travels in a year against the background of stars is called ecliptic, and the period of one revolution along the ecliptic is called a sidereal year. The sun moves across the sky, moving from one constellation to another, and completes a full revolution throughout the year.
Earth is one of the planets solar system. It revolves around the Sun in an elliptical orbit and rotates on its own axis. The movement of the Earth around the Sun and a certain tilt of the Earth's axis lead to the change of seasons. As the Earth moves around the Sun, the Earth's axis remains parallel to itself.
Moon- Earth satellite closest to Earth heavenly body. It rotates around the Earth in the same direction as the Earth around its axis, and together with the Earth it revolves around the Sun.
All planets revolve around the Sun in the same direction. The planet, moving in the same direction as the Sun and the Moon, after some time slows down, then stops, moves in the opposite direction and, after another stop, again changes the direction of movement to the original.
§ 65. Reflection of light. Law of Light Reflection
You already know that light from a source or from an illuminated body is perceived by a person if the light rays enter the eyes. From the source S, let us direct a beam of light through a slit onto the screen. The screen will be illuminated, but we will not see anything between the source and the screen (Fig. 134, a). Now let’s place an object between the source and the screen: a hand, a piece of paper. In this case, the radiation, having reached the surface of the object, is reflected, changes its direction and enters our eyes, i.e. it becomes visible.
Rice. 134. Rays of light falling on the screen
If you add dust to the air between the screen and the light source, it becomes all visible beam of light (Fig. 134, b). Dust particles reflect light and direct it into the observer's eyes.
This phenomenon is often observed when the sun's rays penetrate the dusty air of a room.
It is known that on a sunny day, using a mirror you can create a light “bunny” on the wall, floor, or ceiling. This is explained by the fact that a beam of light, falling on a mirror, is reflected from it, i.e., changes its direction.
A light “bunny” is a trace of a reflected beam of light on a screen. Figure 135 shows the reflection of light from a mirror surface.
Rice. 135. Reflection of light from a mirror surface
Line MN is the interface between two media (air, mirror). A beam of light falls on this surface from point S. Its direction is set by the ray SO. The direction of the reflected beam is shown by the OB beam. Beam SO - incident ray, beam OB - reflected beam. From the point of incidence of the ray O, a perpendicular OS is drawn to the surface MN. The angle SOC formed by the incident ray SO and the perpendicular is called the angle of incidence(α). The angle COB formed by the same perpendicular OS and the reflected ray is called reflection angle (β).
Thus, the reflection of light occurs according to the following law: the incident and reflected rays lie in the same plane with a perpendicular drawn to the interface between the two media at the point of incidence of the ray.
The angle of incidence α is equal to the angle of reflection β.
∠ α = ∠ β.
Any non-mirror, i.e. rough, non-smooth, surface scatters light, since it has small protrusions and depressions.
§ 66. Flat mirror
Flat mirror called a flat surface that specularly reflects light. The image of an object in a flat mirror is formed behind the mirror, i.e., where the object actually does not exist.
Let diverging rays SO, SO 1, S0 2 fall on the mirror MN from a point light source S (Fig. 139).
According to the law of reflection, the SO ray is reflected from the mirror at an angle of 0°; beam S0 1 - at angle β 1 = α 1; the beam S0 2 is reflected at an angle β 2 = α 2 . A diverging beam of light enters the eye. If we continue the reflected rays behind the mirror, they will converge at point S 1. A diverging beam of light enters the eye, emanating as if from point S 1 This point is called virtual image of point S.
Rice. 139. Image of an object in a flat mirror
S 1 O = OS. This means that the image of the object is located at the same distance behind the mirror as the object is located in front of the mirror.
§ 67. Refraction of light. Law of light refraction
A medium in which the speed of light propagation is slower is an optically denser medium.
Thus, the optical density of the medium is characterized by different speeds of light propagation.
This means that the speed of light propagation is greater in an optically less dense medium. When a light beam falls on a surface separating two transparent media with different optical densities, such as air and water, part of the light is reflected from this surface, and the other part penetrates into the second medium. When passing from one medium to another, a ray of light changes direction at the boundary of the media (Fig. 144). This phenomenon is called refraction of light.
Rice. 144. Refraction of light when a beam passes from air to water
Let's take a closer look at the refraction of light. Figure 145 shows: incident ray JSC, refracted ray OB and perpendicular to the interface between the two media, drawn to the point of incidence O. Angle AOS - angle of incidence (α), angle DOB - angle of refraction (γ).
When passing from air to water, a ray of light changes its direction, approaching the perpendicular CD.
Water is a medium optically denser than air. If water is replaced by some other transparent medium, optically denser than air, then the refracted ray will also approach the perpendicular. Therefore, we can say that if light comes from an optically less dense medium to a more dense medium, then the angle of refraction is always less than the angle of incidence
A ray of light directed perpendicular to the interface between two media passes from one medium to the other without refraction.
When the angle of incidence changes, the angle of refraction also changes. The greater the angle of incidence, the greater the angle of refraction
In this case, the relationship between the angles is not preserved. If we compose the ratio of the sines of the angles of incidence and refraction, then it remains constant.
For any pair of substances with different optical densities we can write:
where n is a constant value independent of the angle of incidence. It is called refractive index for two environments. The higher the refractive index, the more strongly the ray is refracted when passing from one medium to another.
Thus, the refraction of light occurs according to the following law: the incident ray, the refracted ray, and the perpendicular drawn to the interface between the two media at the point of incidence of the ray lie in the same plane.
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant value for two media:
§ 68. Lenses. Lens power
Lenses are transparent bodies bounded on both sides by spherical surfaces.
There are two types of lenses - convex and concave.
Rice. 151. Types of lenses:
a - convex; b - concave
The straight line AB passing through the centers C 1 and C 2 (Fig. 152) of the spherical surfaces limiting the lens is called optical axis.
Rice. 152. Optical axis of the lens
By directing a beam of rays parallel to the optical axis of the lens at a convex lens, we will see that after refraction in the lens, these rays intersect the optical axis at one point (Fig. 153). This point is called lens focus.
Each lens has two focal points - one on each side of the lens.
Rice. 153. Converging lens:
a - the passage of rays through the focus; b - its image in the diagrams
The distance from a lens to its focus is called focal length of the lens and is designated by the letter F.
A convex lens collects rays coming from a source. Therefore, a convex lens is called collecting.
This lens is called dispersive.
Rice. 154. Diverging lens:
a - the passage of rays through the focus; b - its image in the diagrams
Lenses with more convex surfaces refract rays more than lenses with less curvature. If one of the two lenses has a shorter focal length, then it gives greater magnification. The optical power of such a lens is greater.
Lenses are characterized by a value called the optical power of the lens. Optical power is designated by the letter D.
The optical power of a lens is the reciprocal of its focal length.
The optical power of the lens is calculated by the formula
The unit of optical power is the diopter (dopter).
1 diopter is the optical power of a lens whose focal length is 1 m.
§ 69. Images given by a lens
Using lenses, you can not only collect or scatter light rays, but also obtain various images of an object. If we place a candle between the lens and its focus, then on the same side of the lens where the candle is located, we will see an enlarged image of the candle, its direct image
If a candle is placed behind the focus of the lens, then its image will disappear, but on the other side of the lens, far from it, a new image will appear. This image will be enlarged and inverted in relation to the candle.
If you bring an object closer to the lens, its inverted image will move away from the lens, and the size of the image will increase. When the object is between points F and 2F, i.e. F< d < 2F, его действительное, увеличенное и перевёрнутое изображение будет находиться за двойным фокусным расстоянием линзы (рис. 159)
If an object is placed between the focus and the lens, i.e. d< F, то его изображение на экране не получится. Посмотрев на свечу через линзу, мы увидим imaginary, direct And enlarged image.It is between focus and double focus, i.e.
F< f < 2F.
Thus, the dimensions and location of the image of an object in a converging lens depend on the position of the object relative to the lens.
§ 70. Eye and vision
The human eye has an almost spherical shape and is protected by a dense membrane called the sclera. The anterior part of the sclera - the cornea 1 - is transparent. Behind the cornea (cornea) is the iris 2, which different people may have different colour. Between the cornea and the iris there is a watery fluid.
Rice. 163. Human eye
There is a hole in the iris - pupil 3, the diameter of which, depending on the lighting, can vary from approximately 2 to 8 mm. It changes because the iris is able to move apart. Behind the pupil there is a transparent body, similar in shape to a converging lens - this is the lens 4, it is surrounded by muscles 5 that attach it to the sclera.
Behind the lens is the vitreous body 6. It is transparent and fills the rest of the eye. Rear end sclera - the fundus of the eye - is covered with a retina 7 (retina). The retina consists of the finest fibers that, like villi, cover the fundus of the eye. They are branched endings optic nerve, sensitive to light.
Light falling into the eye is refracted on the front surface of the eye, in the cornea, lens and vitreous body(i.e. in the optical system of the eye), due to which a real, reduced, inverted image of the objects in question is formed on the retina (Fig. 164).
Rice. 164. Formation of an image on the retina
Light falling on the endings of the optic nerve, which make up the retina, irritates these endings. Irritations are transmitted along nerve fibers to the brain, and a person receives a visual impression and sees objects. The process of vision is corrected by the brain, so we perceive the object as straight.
How is a clear image created on the retina when we move our gaze from a distant object to a close one or vice versa?
As a result of its evolution, the optical system of the eye has developed a remarkable property that provides images on the retina at different positions of the object. What kind of property is this?
The curvature of the lens, and therefore its optical power, can change. When we look at distant objects, the curvature of the lens is relatively small because the muscles surrounding it are relaxed. When looking at nearby objects, the muscles compress the lens, its curvature, and therefore the optical power, increases.
Based on the requirements of the Federal State Educational Standard, where Special attention is focused on students acquiring experience in design and educational and research activities, I propose the development of a project on the topic: “Optical phenomena.”
When working on this project, students develop a meta-subject aspect of their activity; which allows students to formulate the purpose of their work, define tasks and predict the result of their activities. Work on this project is aimed at solving interesting task associated with optical phenomena, is practical in nature and publicly allows you to show the achieved result.
Depending on the characteristics of the class, this project can be expanded to a large scale. research work or, conversely, reduced to the boundaries of a specific 8th grade topic. Students in the class are invited to join one of 4 groups: a) public opinion researchers; b) theorists; c) experimenters; Each group receives its own task. Collects material with the help and recommendations of the teacher. Presents the report in the form of a presentation, practical work and demonstration experiment.
Depending on which grade 8, 9 or 11 this project will be implemented in, the material can be expanded or reduced; Whether the project will be presented at a conference about what light is or will be limited only to the scope of the lesson, all this depends on the time possibilities and desires of the teacher and students. Variations on this topic a lot of. This is one of the possible options.
An educational project is independent decision students or a group of students on any problem and a public presentation of the results of this work. This project is information and research with elements of practical orientation. New types of student activities - independent search for information, analysis of this information, selection of necessary information, use various types information.
Design, manufacturing, creation, selection of experiments and experimental equipment, exchange of information, ability to express one’s point of view, develop it, defend it in a dispute.
Goals: Find out what role light plays in our lives. How did a person gain knowledge about light phenomena, what is the nature of light
Tasks: To trace the experience of mankind in the study and use of light phenomena, to find out the patterns and development of views on the nature of light; conduct experiments confirming these patterns; think over and create demonstration experiments that prove the laws of light propagation in different optical media (reflection, refraction, dispersion, diffraction, interference).
Report of a group of public opinion researchers.
Goals: Show what role light phenomena play in our lives; answer the question: “What do we know about this phenomenon?”
The group studied proverbs, sayings, and riddles related to light phenomena.
- “Even a rotten thing glows in the dark.” (Russian)
- "Shadow high mountain- falls far." (Korean)
- “The tail trails the body, the shadow follows the object.” (Mongolian)
- “The sun is brighter - the shadow is darker.” (Tamil)
- “You can’t run away from your shadow.” (Udmurd).
- “The flower in the mirror is good, but you won’t take it, the Moon is close, but you won’t get it.” (Japanese)
- “It’s darkest before the dawn.” (English)
Puzzles:
For example:
- What can't you hide in a box? (Light)
- You have it, I have it, the oak tree has it in the field, the fish has it in the sea. (Shadow).
- In the morning it's a fathom, at noon it's a span, and by evening it's across the field. (Shadow)
- What can’t you pick up from the Earth? (Shadow and roads).
- From the window to the window the spindle is ready. (Sunbeam).
Proverbs and sayings:
- The sun is shining, but the moon is just shining. (Russian).
- The colors of the rainbow are beautiful, but they are not durable; the colors of pine and cypress are not very beautiful, but they are evergreen. (Chinese).
- Dress up by looking in the mirror, correct yourself by looking at people. (Mongolian).
- You can't make white out of black. (Russian)
- A firefly does not glow in the sun. (Tamil)
The group conducted a small sociological survey
- What do you know about light phenomena?
- Why do people use glasses or contacts?
- What is the connection between our vision and the information we receive from the world around us?
- How does the light from a fire differ from the light from a fluorescent lamp?
Report of a group of theorists.
Goals: Study the laws of light propagation in a homogeneous and inhomogeneous transparent medium; behavior of a light beam at the interface between two media. Arouse cognitive interest, develop research skills: independently search, collect information, observe, analyze, be able to draw conclusions; be able to argue. - “Do we see a ray of light? What is light?
Life on Earth arose and exists thanks to the radiant energy of sunlight.
The fire of a primitive man, oil burning in car engines, the fuel of space rockets - all this is light energy, once stored by plants and animals. Stop the solar flow, and rain will fall on the Earth from liquid nitrogen and oxygen. Temperatures will approach absolute zero.
But it’s not only energy that light brings to Earth. Thanks to the luminous flux we perceive and know the world. Rays of light tell us about the position of near and distant objects, their shape and color.
Light, amplified by optical instruments, reveals to man two worlds that are polar in scale: the cosmic world with its enormous extent and the microscopic world, inhabited by indistinguishable with the naked eye the smallest organisms.
Light allows us to experience the world around us through vision. Scientists have calculated that a person receives about 90% of information about the world around him with the help of light through vision.
The brightest and most beautiful natural phenomena that a person encounters in his life are light. Remember sunrises and sunsets, the appearance of a rainbow, the blue color of the sky, the glare of sunbeams, rainbow colors soap bubbles, and how mysterious and deceptive mirages are!
Man has learned to use light in his various activities. Optical instruments installed on board an aircraft or space station, make it possible to detect oil spills on the sea surface. Laser ray in the hands of a surgeon it becomes a light scalpel, suitable for complex operations on the retina. The same beam at a metallurgical plant cuts massive sheets of metal, and clothing production cuts fabrics. The light beam transmits messages, controls chemical reactions and is used in many other technological processes.
Have you ever thought about these questions:
Why are some objects colored and others white or black?
Why do bodies heat up when sunlight hits them?
Why is the shadow of the feet on the ground from the lantern sharply limited, and the shadow of the head more blurry?
- Light is radiation that is perceived by the eye. This radiation is called visible radiation.
- The radiation energy is partially absorbed by bodies, as a result of which they heat up.
- The bodies from which light emanates are sources of light.
Based on the results of studying this topic, presentations were made on one of the proposed topics:
- Light sources (traditional and alternative).
- From the history of light sources.
- The sun and its influence on life on Earth.
- Solar and Lunar eclipses.
- Optical illusions and mirages.
- Mirrors in human life.
- Camera and projection equipment yesterday and today.
- What is fiber optic?
- The eye is a living optical device.
- How do animals see?
- Telescopes and their history. Observations of the Moon and planets.
- Microscope.
Conclusions: Light is only visible when it hits our eyes.
Light emanating from various objects, entering a person’s eyes, produces an effect, which is then processed by the brain, and we say what we see.
Different bodies reflect, transmit and absorb light differently.
Depending on what phenomenon is playing main role, we divide bodies into transparent and opaque
Physical models:
If the dimensions of a luminous body are much smaller than the distance at which we evaluate its action, then the luminous body is called a point source.
A light ray is a line along which energy from a light source travels.
Light from a source can travel through a vacuum, air, or other transparent medium.
A medium is called homogeneous if it physical properties at different points there are no differences or these differences are so insignificant that they can be neglected.
Law of rectilinear propagation of light:
In a homogeneous transparent medium, light travels in a straight line.
The formation of a shadow is a consequence of the rectilinear propagation of light.
Vision mechanism:
Reports from the experimental team.
Target: find out the dependence of the size of the shadow on the size of objects and on the distances between the source, object and screen; how does a ray of light pass through boundaries? different environments; behavior of a beam when it falls on a triangular prism; how the angle of refraction changes when the angle of incidence changes.
Topics of experimental work:
- Obtain an image of a distant object (for example, a window) on the screen through a pinhole in the cardboard. The hole dimensions are about 5 mm.
- Propagation of light in a homogeneous transparent medium: air, water, glass.
- The formation of shadows behind objects from one or two light sources.
- What happens at the interface between two media: air-glass (frosted, transparent); air-water; air-mirror; air sheets of paper (white, colored, black)
- How does the angle of reflection change when the angle of incidence at the air-mirror (water) boundary changes?
- What happens to a ray of light when it falls on a triangular prism; plane-parallel plate; round flask with water (without water)?
- How does the angle of refraction change when the angle of incidence changes when going from air to water to glass?
- How does the angle of refraction change when the angle of incidence changes when a ray of light passes from water to air; from glass to air?
For laboratory work L-micro optics kit, computer, multimedia projector are used.
Report from the design team.
Goals: Create demonstration experiments; explain the results of observed phenomena. Cultivate accuracy when performing an experiment, observe safety precautions, responsibility, perseverance, and be able to analyze the result obtained.
Experiments in geometric optics.
After studying the literature, several experiments were selected, which they decided to carry out themselves. We came up with experiments, made instruments and tried to explain the results of the experiments.
Equipment: a jar of sour cream, black paint, tracing paper or thin paper, an elastic band and a small candle.
Make a small hole in the bottom of the jar, and use tracing paper instead of a lid, securing it with an elastic band. Light a candle and point the bottom of the jar towards the candle flame. An image of a candle flame will appear on the tracing paper.
Tracing paper is an analogue of our retina. On it the image of a candle is upside down. We also see the world upside down, but our brain processes the image of the eyes and turns it upside down to make it easier for us to perceive information.
Equipment: flashlight, small mirror, foil, small object.
Wrap the end of the flashlight in foil, make a small hole in the foil and direct the flashlight beam at the mirror. A ray of light will be reflected from the mirror and hit the object. Checking the laws of light reflection.
Equipment: stick a small mirror on a white piece of paper, a flashlight.
The mirror in this experiment looks like a black rectangle. Why?
Equipment: glass, two identical candles, matches.
Place the candles at the same distance from the glass with different sides. Light one of the candles. Move the candle so that the flame of the burning candle coincides with the wick of the unlit candle. The light from the flame of a burning candle is reflected from the glass. This creates the illusion that both candles are burning.
Equipment: transparent container, flashlight, some milk, water, screen.
Point the flashlight beam at the water; the light will come out from the other side of the container. If you shine the flashlight at an angle, pointing the beam slightly upward. After passing through the water, the beam will end up at the bottom of the vessel wall. If you add milk to the water, the light will be better visible. The surface of the water acts like a mirror.
Literature:
- Textbook "Physics-9" author. G.N. Stepanova.
- "Light" ed. IN AND. Kuznetsov - Moscow: “Pedagogy”, 1977.
- “Physics in proverbs and sayings” S.A. Tikhomirov - Moscow: Interprax, 1994.
- “Do you know physics?” ME AND. Perelman - Kvant library issue 82, 1992.
- "Big Book scientific experiments for children and adults” M. Yakovleva, S. Bolushevsky. – Moscow: Eksmo, 2013.
- « Project activities students. Physics grades 9-11. ON THE. Lymarev. – Volgograd: Teacher, 2008.
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