1. Multiple choice questions. There are ***5 small questions in this question, each with 3 points, and * * * is 15. Only one option in each small question meets the meaning of the question.

1. There are two equal heterogeneous point charges in vacuum. The midpoint o of the connecting line is the coordinate origin, and their perpendicular lines are the X axis. In the figure below, the electric field intensity on the x axis can be correctly expressed by ().

2. Beidou satellite navigation system is a regional three-dimensional satellite positioning communication system (CNSS) independently developed by China. The Beidou satellite navigation system includes 5 synchronous satellites and 30 general orbit satellites. For five of the synchronous satellites, the following statement is true ().

A. it must be in the same position in space. It must be in the same orbit in space.

C. the attraction of the earth to them must be the same. D. They must run at the same acceleration.

3. The resistance of superconductor is zero. If there is a current in a closed superconducting circuit, this current will not generate Joule heat, so it will not disappear by itself. There is a superconducting ring at the position shown in the figure, and there is no current in the ring at this time. Move a bar magnet to point p along the central axis of the ring OO'. The following statement is true ()

A. When the magnet approaches, clockwise induced current is generated in the ring when viewed from left to right.

B. When the magnet approaches, the ring is attracted by the magnet.

C when the magnet stops at point p, the current in the ring disappears immediately.

D, after the magnet stops at point P, the ring is repelled by the magnet.

4. EMU is composed of powered cars and unpowered cars according to certain rules. It is known that the quality of emus and carriages is the same, the rated power provided by each emu is the same, and the resistance of emus is directly proportional to the speed. When the existing EMU has only one power car, the maximum speed is V. If the maximum speed is to be raised to 2v, the number of non-power cars to power cars should be ().

A.2 B.3 C.4 D.8

5. The speed of water flow in a river is 2m/s, and the speed of the ship relative to still water is 1m/s, so that the bow of the ship can cross the river just across the river bank and drive to point B on the other side of the river. Now let the bow point to a certain direction upstream to cross the river, and then the boat ()

A. the location to reach the other side of the river must be on the right side of point B.

B. the location to reach the other side of the river must be on the left side of point B.

It is still possible for C to reach point B, but it takes longer to cross the river than before.

It is still possible for D to reach point B, but the crossing time is shorter than before.

Second, multiple choice questions. There are ***4 small questions in this question, each with 4 points, * * meter 16 points. Each small question has multiple options that match the meaning of the question. All the answers are correct, 4 points, 2 points that are correct but incomplete, and 0 points that are wrong or not answered.

6. As shown in the figure, R is a photoresistor. When the light intensity it receives increases ().

A. the light bulb l is dimmed

B. the voltage on the photoresistor r increases.

C. the reading of voltmeter v drops.

D. the charging capacity of capacitor c is increased.

7. The maintenance personnel of the power supply company use AC ammeter to monitor the strong current and high voltage in the power supply line. The instruments used are current transformer and voltage transformer, and the wiring is as shown in the figure. Where n 1, n2, n3 and n4 are the turns of four groups of coils respectively, and A and B are two AC meters. The following statement is correct ().

A.a is current transformer, n 1 < N2, and a is ammeter.

B.b is a voltage transformer, n3 >；; N4 and a are ammeters.

C.b is current transformer, n3 < n4, and b is ammeter.

D.A is voltage transformer, N 1 > N2, and a is voltmeter.

8. A particle is subjected to a constant force, and the image of the relationship between its kinetic energy and time may be ()

9. As shown in the figure, two objects A and B are placed on a rough horizontal surface and connected by a light spring, the length of which is greater than the original length. If the object B is pulled to the right with a horizontal force F that gradually increases from zero until A is about to move, during this process, the friction force f 1 changes to B and the friction force f2 changes to A ().

A.f 1 decreases first, then increases, and then remains the same.

B.f 1 remains unchanged first, then becomes larger and then smaller.

C.f2 becomes larger first, and then remains the same.

D.f2 remains unchanged at first, and then becomes larger.

Three. Answer: This question is divided into two parts: the required question (questionNo. lO, 1 1) and the multiple-choice question (questionNo. 12), of which * * * accounts for 42 points.

Must do the problem

10.( 10) According to related experiments, answer the questions:

(1) A vernier caliper with 50 equally divided small scales with a total length of 49 mm It is used to measure the width of the workpiece and the reading is _ _ _ _ _ _ _ _ mm as shown in Figure A; The reading of the screw micrometer in Figure B is _ _ _ _ _ _ _ mm. 。

(2) In the experiment of "Verifying the Law of Conservation of Mechanical Energy", a classmate used the device shown in Figure A to get a paper tape, but the starting point was ambiguous. Take the clear points typed in the back for learning, and measure the distances from B, C, D, E and F to point A as hB, hC, hD, he and hF respectively. It is known that the time interval between adjacent counting points is t and the weight of the weight is m.

(1) In the experiment, the connection between the two limit holes of the dot timer must be kept _ _ _ _ _ _.

(2) When hitting point E, the expression of kinetic energy of the heavy object is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(3) in the v2-h coordinate system, track the coordinates corresponding to points B, C, D and E, as shown in Figure B. If these coordinates can be connected into a straight line, it is necessary to _ _ _ _ _ to judge whether the mechanical energy is conserved during the falling of heavy objects.

1 1.(8 points) In order to measure the internal resistance of the voltmeter, the following equipment is given:

A. voltmeter (0-3v, internal resistance is about several thousand ohms) B. ammeter (0- 1mA)

C. ammeter (0-1a) D. sliding rheostat (0-50 ohms)

E. power supply (2 1.5V dry batteries) F. several switches and wires.

(1) In order to obtain multiple sets of measurement data, please design the circuit diagram and draw it in the dotted box.

(2) In the experiment, the ammeter should be selected as B instead of C. The reason is _ _ _ _

(3) The following table shows six groups of data measured in this experiment.

Please draw some points on the coordinate paper and make a U-I diagram.

(4) According to the U-I diagram, calculate the internal resistance of the voltmeter _ _ _ _ _ _ _ _ _ kω.

12. Select the question. This question includes three small questions, A, B and C. If all three questions are done, you will be graded according to two questions, A and B..

A. (optional module 3-3)( 12 points)

(1) Xiao Zhang observes the movement of tiny chalk powder suspended in water under a microscope. He recorded the position of small particles on the coordinate paper every once in a while, as shown in the figure, the following judgment is correct _ _ _ _ _

A. The dotted line in the figure is the movement track of chalk powder.

B. The picture shows the movement track of water molecules.

C. Generally speaking, the movement of chalk powder is irregular.

D. The dotted line in the figure indicates that the movement of water molecules in a short time is regular.

(2) The sunshine in summer warms the earth and heats the air near the ground, forming a warm air mass that rises to the sky and gradually expands. Because the volume of the heater is very large, the heat exchange with the outside atmosphere can be ignored, so the heater will play the role of _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(3) To celebrate Teachers' Day, a school bought a 20L hydrogen bottle to inflate the hydrogen balloon. The initial pressure of hydrogen in the hydrogen bottle is 3atm, the volume of each hydrogen balloon is 2L, and the pressure of gas in the hydrogen balloon after inflation is 1.2atm. If the temperature change of hydrogen during inflation is not considered, how many hydrogen balloons can be filled in the hydrogen bottle?

B (optional module 3-4) (12 points)

(1) As shown in the figure, when two shear waves with the same frequency meet at a certain moment, the solid line indicates the peak and the dotted line indicates the trough, then _ _ _

Point a is always at the highest point.

B.n is always at the bottom.

C.p point vibration strengthening

D.q-point vibration is weakened

(2) The waveforms of a series of harmonic shear waves at 2)t = 0 are shown in the figure. The simple harmonic motion expression of a particle in a medium at x=2m along the y axis is y= 10sin(5πt)cm. Then the wave propagation direction of this train is _ _ _ _ (please fill in "+x" or "-x"), and the wave speed is _ _ _ _ _ _ _ m/s.

(3) There is a pool in the park, and there is a light source at the depth of m underwater. Given that the refractive index of water is 4/3, find the water surface area irradiated by point light source.

C (optional module 3-5) (12 points)

(1) If the following four particles have the same kinetic energy, the largest de Broglie wavelength is ().

A. electron neutron proton alpha particles

(2) The partial energy levels of hydrogen atoms are shown in the figure. It is known that the photon energy of visible light is between 1.62eV and 3. 1 1eV, so the hydrogen atom in the ground state _ _ _ _ _ _ _ _ _ _ _ _ (optional "Yes" or "No") absorbs many visible light photons to make it jump to the high energy level. When a hydrogen atom transitions from a high energy level to a ground state, the wavelength of light emitted is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

(3) On a smooth horizontal plane, a ball A with a mass of 3kg and a speed of 5m/s collides with a static ball B with a mass of 6kg, and the speed of the ball B after collision is 3m/s, so find the speed of the ball A after collision.

4. Calculation question: This question is entitled ***4 small questions, and * * * is 47 points. When answering, please write down the necessary words, equations and important calculation steps. Only write down the questions that can't be scored and have numerical calculation in the final answer. The values and units must be clearly written in the answer.

13.( 15 minutes) Two parallel smooth metal guide rails are vertically placed with an interval of L, and the upper ends are connected with a resistor with a resistance of R through wires. There are n strip-shaped uniform magnetic fields, the direction of which is perpendicular to the plane of the guide rail. The width of the magnetic field area is a, and the spacing is also a. A conductor bar (excluding resistance) with mass m and length l is perpendicular to the guide rail, and it starts to release at the position A far away from the magnetic field area 1, and never leaves the guide rail again, and moves at a constant speed every time it enters the magnetic field area. ask

(1) the magnitude of the magnetic induction intensity in the I region;

(2) Time for the conductor bar to pass through the magnetic field region 2;

(3) The total electric heat generated on the resistor R during the process of the conductor bar falling from the beginning to passing through the magnetic field region N. ..

14.( 16 minutes) As shown in the figure, a semi-cylinder with a radius of 1m is fixed on a horizontal plane, and the ball A and the ball B are connected by a light rope and placed on a smooth cylindrical surface, and the angles with the vertical are 37 and 53 respectively. There is a special area on the right side of Oo, which can exert a vertical constant force on ball A, but no force on ball B. At a certain moment, the ball is disturbed, loses its balance and starts to move from rest. A goes up along the cylindrical surface and B goes down along the cylindrical surface. As soon as the ball A entered the special area, it cut the light rope, just left the cylindrical surface and fell to the horizontal plane. It is known that the mass of ball A is 1Kg, SIN 37 = 0.6, cossin37 =0.8, and the acceleration of gravity g= 10m/s2. ask

(1)B ball mass

(2) The supporting force of the cylinder to the ball A before the ball A enters the special area.

(3) The distance between the falling point of ball A and point O. ..

15.( 16 minutes) As shown in the figure, in the first quadrant, there is a uniform magnetic field perpendicular to the paper, and the magnetic induction intensity in both areas is B. There is a small hole at the origin O. A bunch of positively charged particles with mass m and charge q enter the magnetic field along the X axis through the small hole, and finally leave the magnetic field through the X axis or Y axis. It is known that the velocity of incident particles is between zero and a certain maximum, and the particle with the maximum velocity is 0.

(1) The maximum distance between the particle emission point and the origin o on the y axis.

(2) The X-axis coordinate of the particle with the maximum velocity when leaving the magnetic field.

(3) Time range of all particles moving in the magnetic field.