volume one
First, multiple choice questions
1, which belongs to the reflection of light, is (c) the reflection of Mizukamiyama.
2. The most practical one is (b) 50g of an egg.
3, the correct is (b) is not easy to conduct electricity called insulator.
4.(a) Atoms consist of nuclei and extranuclear electrons.
5. (d) It is correct that B-ultrasound is ultrasonic.
6. Correct (c) At the same depth, the pressure inside the liquid is equal in all directions.
7. The higher the temperature (C) of hot water and cold water, the more intense the molecular thermal movement.
8. Safe use of electricity (d) One plug of the three-pin plug is connected with the metal shell of the electrical appliance.
9. shenzhou spaceship (B) is docked and relatively static.
10, on energy (c) Nuclear waste destroys the environment and cannot be discarded at will.
1 1, the total mechanical energy of the rocket is unchanged when it is lifted off the ground (d).
12, the little ant holds the fruit (1) Gravity and supporting force are a pair of balancing forces.
13. Submarine (a) floats and sinks by changing its own gravity.
14, electromagnetic induction A and live wire B. Choose (B) A as other energy that can be converted into electric energy.
Second, fill in the blanks
15, the force in the opposite direction of the ship changes the object (moving state), and the force acts (mutually).
16, household voltage (220)V, electrical appliances (and).
17, water refrigeration (specific heat capacity) is large, and wood is drilled for fire (doing work)
18, stone mass (52)g, currently (2.4) a.
19, the density is (a), and the density of a is (1.5)g/cm3.
20. When the submersible "Jilong" dives, the water pressure will (increase), and the pressure at 5000m is (5. 15x 107)Pa.
2 1, the slip p moves to the left, the ammeter will (become larger) and the voltmeter will (become smaller).
20. A parallel water heater circuit needs (2 100)S to open and close S and in (heat preservation).
Third, drawing and calculation
23, omitted
24.( 1) Xiao Qiang's gravity is (600 N). (2) The pressure of standing with both feet is (1.2x 104Pa).
25, local short circuit, (1) close the switch, the power supply is 10W (2) open s, and the current is 0.4A
Fourth, experiment and inquiry.
26.( 1) The method used by Xiao Cong is (C control variable method). (2) The convex lens is imaged as a (reduced) image of 28CM. In order to become an enlarged image, the candle moves towards (near) the convex lens.
27. When (1) is connected, the switch (OFF) (2) changes from 5 ohms to 10 ohms, and the sliding switch moves to the right. When the observed voltage is (1.5)V, write down the current value. Move the slip to the maximum, the voltmeter is greater than 1.5V, and select (b) the maximum slip is too small. Volume b
First, choose
1, thermal phenomenon, correct choice (d), mineral water taken out of the freezer in summer, the surface is wet first and then dry, it is liquefied first and then evaporated.
2, light phenomenon, correctly choose (a) concave lens to correct myopia.
3, seagull plane, choose (D) when flying, by transmitting and receiving electromagnetic waves to contact with the ground.
4, friction analysis, choose (A B) friction as sliding friction, the direction of friction against B is right.
5, circuit slide rail, false slide, select (B D) voltmeter as 2V, and the object moves 5CM to the left. Before measurement, P is at a certain point of the resistance wire, and the maximum measurable distance is 30CM.
Second, comprehensive questions
6.( 1) sliding variable selection (b), 50 euros,1.5a.
(2) Slip P (from B to A) Rx = (50) Ω 7, (1) for 4-6 seconds, and the work done by the horizontal rope on the pulling force of A is 74 J.
(2) 2-4 seconds, and the working power of Gb is 25 watts.
(3) 0-2 seconds, the friction force of A is 15N 2-4 seconds, and the friction force of A is 18.5N (this question is correct, generally full marks).