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Вопрос 1
Which of the following physical quantities is not a vector?
Magnetic flux density
Momentum
Electric field strength
Potential energy
Вопрос 2
The gravitational force that an object experiences on Mars is 1/3 of that it experiences on Earth. An object with mass $m = 4.8$ kg weighs ( ) on Mars. ($g = 10$ m/s²)
16 N
144 N
24 N
48 N
Вопрос 3
A spring with spring constant $k = 100$ N/m stretches from 10 cm to 15 cm under force $F$. The magnitude of $F$ is ( ).
5 N
15 N
25 N
10 N
Вопрос 4
An $m = 4$ kg object rests on a horizontal surface with friction coefficient $\mu = 0.1$. If pulled by a 2 N horizontal force, the frictional force is ( ). ($g = 10$ m/s²)
2 N
3 N
4 N
6 N
Вопрос 5
An object is acted upon by three forces: $F_1 = 2$ N, $F_2 = 4$ N, $F_3 = 6$ N. The maximum possible resultant force is ( ).
12 N
10 N
24 N
0 N
Вопрос 6
An $m = 2$ kg object on a smooth horizontal surface moves in a straight line with constant acceleration from rest under a horizontal force $F$. If it displaces 8 m in 2 s, then $F$ is ( ).
8 N
6 N
2 N
10 N
Вопрос 7
An object accelerates uniformly in a straight line from rest at $a = 2$ m/s² on a smooth horizontal surface. Its velocity at $t = 4$ s is ( ).
2 m/s
16 m/s
4 m/s
8 m/s
Вопрос 8
An object falls freely from rest at a height of 100 m. Its height at $t = 4$ s is ( ). ($g = 10$ m/s²)
10 m
45 m
80 m
20 m
Вопрос 9
An $m = 5$ kg object slides down a smooth incline plane with an angle of 30° to the horizontal. It starts from rest, and its displacement in 2 s is ( ). ($g = 10$ m/s²)
10 m
4 m
5 m
2 m
Вопрос 10
An object of mass 2 kg is acted upon by two forces of magnitudes 6 N and 8 N. Its maximum acceleration is ( ).
5 m/s²
4 m/s²
3 m/s²
7 m/s²
Вопрос 11
In a uniform magnetic field, a straight wire with length 0.5 m is placed perpendicular to the direction of the magnetic field. When passing through a current of 10 A it experiences an Ampere force of 1.5 N. The magnitude of the magnetic induction intensity is ( ).
0.1 T
0.3 T
0.2 T
0.4 T
Вопрос 12
A particle moves in uniform circular motion with a speed of $v = 6$ m/s and a radius of $R = 3$ m. Its angular velocity is ( ).
3 rad/s
$3\pi$ rad/s
2 rad/s
$2\pi$ rad/s
Вопрос 13
An object moves along two semicircles of radius $R = 6$ m from point A through B to C in $t = 4$ s. The magnitude of its average velocity is ( ).
12 m/s
$6\pi$ m/s
$3\pi$ m/s
6 m/s
Вопрос 14
Which of the following statements about distance and displacement is correct?
The magnitude of displacement and the distance traveled can be equal
The magnitude of displacement and the distance traveled are never equal
Distance is a vector; displacement is a scalar
Both distance and displacement are vectors
Вопрос 15
An object with mass $m = 0.2$ kg moves in a straight line at a constant speed $v = 20$ m/s on a smooth horizontal surface. Its momentum is ( ).
0.4 kg·m/s
4 kg·m/s
0.8 kg·m/s
8 kg·m/s
Вопрос 16
An $m = 5$ kg object slides down a smooth incline plane with an angle of 30° to the horizontal. It starts at rest from a height of 20 m. The magnitude of its gravitational impulse over 2 s is ( ). ($g = 10$ m/s²)
100 N·s
25 N·s
200 N·s
50 N·s
Вопрос 17
The graph of displacement (x) of a toy car moving in a straight line vs time (t) is shown. Which statement is correct?
Within 4-5 seconds, the speed of the toy car is 0.8 m/s
Within 0-5 seconds, the average speed of the toy car is 0.8 m/s
Within 0-4 seconds, the displacement of the toy car is 8 m
Within 0-4 seconds, the speed of the toy car is 1.0 m/s
Вопрос 18
A horizontal force $F = 20$ N is applied to a 10 kg object, causing it to move 5 m along a rough horizontal surface with friction force $f = 5$ N. The work done by $F$ is ( ).
75 J
25 J
−25 J
100 J
Вопрос 19
A 3 kg object on a smooth horizontal surface changes its speed from 2 m/s to 6 m/s due to an external force. The work done by this force is ( ).
60 J
54 J
6 J
48 J
Вопрос 20
When light enters a medium from air, with an angle of incidence $i = 60°$, the angle of refraction is $r = 30°$. If the refractive index of air is $n = 1$, the refractive index of the medium is ( ).
$\sqrt{3}$
1.5
$\sqrt{2}$
$\sqrt{5}$
Вопрос 21
A spring oscillator undergoes simple harmonic motion. It completes one full oscillation in 2 s. Its frequency is ( ).
0.5 Hz
0.2 Hz
5 Hz
2 Hz
Вопрос 22
A sound wave with frequency $f = 200$ Hz travels at $v = 340$ m/s in air. Its wavelength is ( ).
3.4 m
1.7 m
680 m
6.8 m
Вопрос 23
In a vacuum, two point charges separated by $d$ exert a force $F$ on each other. If one charge's magnitude is doubled, keeping the distance unchanged, the Coulomb force is ( ).
1/4 times
1/2 times
2 times
4 times
Вопрос 24
If a water droplet with zero initial velocity falls from a 5 meter high eaves (excluding air resistance), the speed at which the water droplet falls to the ground is ( ). ($g = 10$ m/s²)
5 m/s
2 m/s
10 m/s
20 m/s
Вопрос 25
The field lines of a certain electric field are shown in the figure. If equal point charges are placed at points a and b in this field, the relationship between the forces $F_a$ and $F_b$ acting on these charges is ( ).
$F_a = F_b$
$F_a > F_b$
$F_a < F_b$
$F_a \geq F_b$
Вопрос 26
Two resistors of 200 Ω and 300 Ω are connected in parallel. The total resistance is ( ).
500 Ω
120 Ω
100 Ω
600 Ω
Вопрос 27
Two resistors $R_1 = 10$ Ω and $R_2 = 30$ Ω are connected in parallel to a circuit with voltage $U = 12$ V. The ratio of the current passing through the resistors $I_1 : I_2$ = ( ).
1 : 1
1 : 2
4 : 3
3 : 1
Вопрос 28
A certain mass of ideal gas, with its temperature kept constant and pressure reduced, its volume would ( ).
remain unchanged
decrease
all options above are possible
increase
Вопрос 29
A point charge of $3.0 \times 10^{-9}$ C is placed in an electric field of $6.0 \times 10^4$ N/C. It experiences an electric force of ( ).
$1.8 \times 10^{5}$ N
$1.8 \times 10^{-4}$ N
$2.0 \times 10^{-4}$ N
$1.8 \times 10^{-5}$ N
Вопрос 30
The SI units for magnetic flux density $B$ and magnetic flux $\phi$ are, respectively, ( ).
Tesla, Weber
Pascal, Hertz
Joule, Watt
Ampere, Volt
Вопрос 31
When a light ray hits a glass-air interface at an angle of incidence 30°, the angle between the reflected and incident rays is ( ).
90°
60°
45°
30°
Вопрос 32
A 0.2 m wire carrying a constant current $I$ is placed in a uniform magnetic field with $B = 0.8$ T. If the maximum Ampere force is $F = 0.08$ N, the current is ( ).
0.5 A
0.2 A
2 A
5 A
Вопрос 33
An ideal gas undergoes an isobaric process from state A to B. At state A: $V_1 = 1.5$ m³, $T_1 = 300$ K. At state B: $T_2 = 400$ K. The volume at state B is ( ).
6 m³
4.5 m³
1.5 m³
2 m³
Вопрос 34
As shown in the figure, there is an electric field in space with two points a and b. Which of the following statements is correct?
The electric field strength at point b is greater than that at point a
The electric field strength at point a is greater than that at point b
This electric field is a uniform electric field
The electric field strength at points a and b is the same
Вопрос 35
An $m = 20$ kg child, with a speed of $v = 6$ m/s, jumps onto a stationary cart on a smooth horizontal surface. Given that the mass of the cart is $M = 40$ kg, their final common velocity is ( ).
6 m/s
3 m/s
2 m/s
4 m/s
Вопрос 36
A basketball of mass 0.5 kg bounces from the ground to a height of 1 m and returns to the ground. The total change in gravitational potential energy is ( ). ($g = 10$ m/s²)
0 J
0.5 J
10 J
5 J
Вопрос 37
Two resistors $R_1 = 10$ Ω and $R_2 = 30$ Ω are connected in parallel to a circuit with voltage $U = 12$ V. The ratio of the current passing through the resistors $I_1 : I_2$ = ( ).
1 : 1
1 : 2
4 : 3
3 : 1
Вопрос 38
Two equal but opposite charges A and B, each with charge $Q = \pm 3.0 \times 10^{-9}$ C, are fixed $r = 6$ cm apart in vacuum. Given $K = 9 \times 10^9$ N·m²/C², the electric field strength at the midpoint of A and B is ( ).
0 N/C
$1.5 \times 10^4$ N/C
$3.0 \times 10^4$ N/C
$6.0 \times 10^4$ N/C
Вопрос 39
A ball is thrown horizontally from a height $h = 20$ m with $v_0 = 20$ m/s. Ignoring air resistance, its velocity when it lands is ( ). ($g = 10$ m/s²)
40 m/s
$40\sqrt{2}$ m/s
$20\sqrt{2}$ m/s
20 m/s
Вопрос 40
If two objects A and B with equal mass are placed on a horizontal disk rotating uniformly around the vertical axis, and the two objects remain stationary relative to the disk, then ( ).
the angular velocity of A is smaller than that of B
the angular velocity of A is greater than that of B
the angular velocity of A is the same as B
the linear velocity of A is the same as B
Вопрос 41
When a point charge of $+4 \times 10^{-6}$ C is moved from point A to B in an electric field, the electric field force does a negative work of $8 \times 10^{-4}$ J. The potential difference between A and B is ( ).
−200 V
−2000 V
200 V
2000 V
Вопрос 42
A conducting sphere A carrying a positive charge of $8q$ and a similar sphere B carrying $-4q$ are at distance $r$. If the two spheres are put in contact and returned to original positions, their new Coulomb force becomes ( ).
$\dfrac{1}{8}$ times
8 times
$\dfrac{1}{4}$ times
4 times
Вопрос 43
A bullet traveling horizontally penetrates two identical wooden blocks, slowing from 700 m/s to 500 m/s after the first block. Its speed after the second block is ( ).
100 m/s
300 m/s
50 m/s
200 m/s
Вопрос 44
An $m = 2$ kg object is stationary on a smooth horizontal surface. It is then subjected to a horizontal force $F$. The change of $F$ with time is shown in the figure (F=4N for 0-1s, F=6N for 1-2s). The kinetic energy at $t = 2$ s is ( ).
25 J
36 J
16 J
50 J
Вопрос 45
A horizontal platform AB has height $h = 0.80$ m. A block slides from A with $v_0 = 6.0$ m/s. Friction coefficient $\mu = 0.25$. Length AB = 2.2 m. The horizontal landing distance from the platform bottom is ( ). ($g = 10$ m/s²)
1.5 m
2 m
3 m
1 m
Вопрос 46
Parallel metal rails are connected with resistor R. Wire ab can slide without friction in a uniform magnetic field. When ab moves uniformly to the right, which statement is correct?
If resistance R is increased, the force pulling wire ab can be increased
The higher the speed of ab, the smaller the required pulling force
If ab reaches a certain speed and external force is removed, ab can maintain uniform motion
Wire ab is subjected to both tension force and magnetic field force
Вопрос 47
A block of mass $m = 0.1$ kg with charge $Q = -2.0 \times 10^{-4}$ C is placed on a horizontal desktop in a uniform electric field. Friction $f = 0.2$ N, electric force $F = 0.4$ N directed right. The net work done by resultant external force in 2s is ( ).
3.2 J
1.6 J
0.8 J
2.4 J
Вопрос 48
Three identical point charges are fixed at vertices a, b, c of an equilateral triangle on a smooth insulated surface. A detector is at center D, another at point F (symmetric to E relative to charge c). Which statement is correct?
The readings at detectors D and F are the same
The readings at detectors E and H are different
If charge c is released, it will undergo uniform acceleration motion
The reading at detector D is zero