Physics Test MCQ Paper for CBSE PMT
CBSE PMT Physics Objective Questions
1. A force of constant magnitude acts continuously on a particle perpendicular to its direction of motion. Consequently the particle moves in a plane. Conclusion is that—
(A) The speed of the particles is constant
(B) The acceleration of the particle is constant
(C) The kinetic energy of the particle goes on continuously changing
(D) The particle moves on a circular path
Ans:-D
2. If the speed and radius of a particle executing a circular motion are both made three-fold, the centripetal force—
(A) Will remain unchanged
(B) Will get nine-fold
(C) Will be one third
(D) Will get three fold
Ans:-D
3. Two cars of masses m1 and m2 are moving on circular tracks of radii r1 and r2 respectively. Their speeds are such that they take equal times in completing one round each. The ratio of the angular speeds of both the cars is—
(A) m1:m2
(B) r1:r2
(C) 1: 1
(D) m1 r2: m2 r1
Ans:-C
4. A ballon filled .with hydrogen gas is tied to the floor of a car with a thread. If the car turns rightward, which way the ballon will go?
(A) Leftward
(B) Rightward
(C) remains stationary
(D) Any side it may take
Ans:-B
5. Angular momentum is—
(A) A scalar quantity
(B) A polar vector
(C) An axial vector
(D) A number
Ans:-C
6. Two balls of 3 kg and 6 kg respectively are fired from a cannon with the same velocity and in the same direction. Let the air resistance be negligible. Which of the following is true?
(A) 3 kg ball will reach the ground first
(B) 6 kg ball will rach the ground first
(C) Both the balls will reach the ground simultaneously
(D) None of the above is correct
Ans:-C
7. It the magnitude of the resultant of two- forces F and F acting at a point be also F, then the angle between these two forces will be—
(A) 0°
(B) 60°
(C) 120°
(D) 90°
Ans:-C
8. A particle is moving eastward with a speed of 5 m/s. Within 10 seconds its velocity changes to 5 m/s northward. The average acceleration within this period is—
(A) zero
(B) 1/√2 m/s2 towards north-west
(C) 1/√2 m/s2 towards north-east
(D) ½ m/s2 towards north-west
(E) ½ m/s2 towards north
Ans:-B
9. A boat whose speed in still water is 5 km/hr, crosses a 1 km wide river within 15 minutes by the shortest possible route. The velocity of river-water in km/hr is—
(A) 1
(B) 3
(C) 4
(D)√41
Ans:-B
10. Which of the following is a vector quantity?
(A) Current density.
(B) Current
(C) Potential
(D) Charge
Ans:-A
10. Some neutron stars are whirling with a speed of 1 rev/sec. If the radius of some such star be 20 km, what will be the acceleration of an object at the equatorial circle of this star?
(A) 20 x 103 m/s2
(B) 120 x 103 m/s2
(C) 8 x 105 m/s2
(D) 4 x 103m/s2
Ans:-C
11. A man is sitting on a whirling stool with his hands outstretched. All of a sudden he shrinks his hands. Now,
(A) His angular velocity will decrease
(B) His moment of inertia will decrease
(C) His angular velocity will remain constant
(D) His angular momentum will increase
Ans:-B
12. A body is acted upon by two forces of 5 newton and 12 newton simultaneously. For the resultant force on it, which of the following is correct?
(A) 7 newton
(B) 17 newton
(C) 10 newton
(D) Any value between 7 newton and 17 newton
Ans:-D
13. What should be the value of the angle of projection for the maximum range in case of an object thrown surface to surface?
(A) 0°
(B) 30°
(C) 45°
(D) 75°
Ans:-C
14. When a horse suddenly gallops, the rider leans—
(A) Forward
(B) Backward
(C) Leftward
(D) Rightward
Ans:-B
15. The dust particles stuck on a coat get off when the latter is beaten by a baton. This is due to—
(A) Their being lighter
(B) The inertia
(C) The baton being heavier
(B) The coat being lighter
Ans:-B
16. The weight of an object is 10 newton. The force with which the earth attracts the object is—
(A) 5 newton
(B) 10kg
(C) 10 newton
(D) 100 kg
Ans:-C
17. The mass of a rocket is 10,000 kg. The velocity of the gases escaping from it is 1,000 m/sec. At what rate should the fuel be burnt so that the rocket may just take off—
(A) 9.8 kg/sec
(B) 19.6kg/sec
(C) 19.6kg/min
(D) 98kg/sec
Ans:-D
18. A bullet of 20 gram, moving with a speed of 400 m/s, gets thrust into a freely suspended wooden block of 900 gram. The speed acquired by the block is—
(A) 88 m/s
(B) 8.7 m/s
(C) 4.4 m/s
(D) 8.88m/s
Ans:-B
19. If the gravity at moon is 1/6 of that on earth, the length of a second’s pendulum situated on the moon will be—
(A) 16.5cm
(B) 20cm
(C) 12cm
(D) 15cm
Ans:-A
20. A man is at rest in the middle of a pond on perfectly smooth ice. He can get himself to the shore by making use of Newton’s—
(A) First law
(B) Second law
(C) Third law
(D) All the laws
Ans:-C
21. Three equal weights A, B and C of mass 2 kg each are hanging on a string passing over a fixed frictionless pulley as shown in ‘the figure. The tension in the string connecting weights B and C is—
(A) Zero
(B) 13N
(C) 3.3 N
(D) 19.6 N
Ans:-B
22. Match List I (Lasers) with List II (Methods) of population inversion to produce laser action) and select the correct answer using the codes given below the Lists:
List I List II
A.He-Neon 1. Molecular collision
B. Argon ion 2. Electric discharge
C. Semiconductor 3. Direct conversion
D.Carbon dioxide 4. Electron impact
Codes:
A B C D
(a) 2 4 3 1
(b) 2 4 1 3
(c) 4 2 3 1
(d) 4 2 1 3
Ans. (a)
23. Match List-I with List-Il and select the correct answer using the codes given below the Lists:
List I List II
(Process) (Approximate energy released in MeV)
A. Fission of one uranium nucleus 1. 2
B Formation of one helium nucleus 2. 8
by fusion
C. Formation of a compound nucleus
by the capture of a neutron . 3. 200
D. Formation of a deuteron by the
capture of a neutron by a proton 4. 28
Codes:
A B C D
(a) 3 4 2 1
(b) 2 4 1 3
(c) 4 2 3 1
(d) 3 1 2 4
Ans. (b)
24. The velocity of longitudinal waves in quartz is 5.46 x 103 m/s. If the thickness of the quartz crystal is 1 mm, then the frequency of the ultrasonic wave generated by it is:
(a) 2.73 kHz
(b) 5.46kHz
(c) 2.73 MHz
(d) 5.46 MHz
Ans. (c)
25. Vander Waals’ equation for real gases is
The dimensions of “a” will be (symbol have their meaning):
(a) [ML5T-2]
(b) [ML3T-2]
(c) [ML-3T-1]
(d) [ML2T-1]
Ans. (a)
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