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Subject physics

Written by Dr. Hamza Farooq (Physics)

24 COMSATS Physics questions with answers and explanations.

Printable worksheet with answer key

All questions with answers
  1. The SI unit of energy is the:

    • 1 Watt
    • 2 Newton
    • 3 Pascal
    • 4 Joule
    Show answer

    Correct answer: Joule

    Energy is measured in joules.

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  2. A force acts on a 5 kg body and gives it an acceleration of 2 m/s². The force is:

    • 1 10 N
    • 2 3 N
    • 3 2.5 N
    • 4 7 N
    Show answer

    Correct answer: 10 N

    F = ma = 5 × 2 = 10 N.

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  3. A body with an initial speed of 5 m/s accelerates at 2 m/s² for 3 s. Its final speed is:

    • 1 11 m/s
    • 2 6 m/s
    • 3 15 m/s
    • 4 30 m/s
    Show answer

    Correct answer: 11 m/s

    v = u + at = 5 + 6 = 11 m/s.

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  4. A current of 2 A flows in a 6 Ω resistor. The potential difference is:

    • 1 12 V
    • 2 3 V
    • 3 0.33 V
    • 4 8 V
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    Correct answer: 12 V

    V = IR = 2 × 6 = 12 V.

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  5. The kinetic energy of a 2 kg body at 3 m/s is:

    • 1 18 J
    • 2 3 J
    • 3 9 J
    • 4 6 J
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    Correct answer: 9 J

    KE = ½ × 2 × 9 = 9 J.

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  6. A force of 20 N moves a body 3 m in its own direction. The work done is:

    • 1 17 J
    • 2 60 J
    • 3 6.7 J
    • 4 23 J
    Show answer

    Correct answer: 60 J

    W = Fd = 60 J.

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  7. A wave has a time period of 0.5 s. Its frequency is:

    • 1 1 Hz
    • 2 5 Hz
    • 3 0.5 Hz
    • 4 2 Hz
    Show answer

    Correct answer: 2 Hz

    f = 1 ÷ T = 2 Hz.

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  8. Which of these is a scalar quantity?

    • 1 Velocity
    • 2 Force
    • 3 Displacement
    • 4 Speed
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    Correct answer: Speed

    Speed has magnitude only.

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  9. Resistors of 6 Ω and 3 Ω are connected in parallel. The equivalent resistance is:

    • 1 2 Ω
    • 2 18 Ω
    • 3 4.5 Ω
    • 4 9 Ω
    Show answer

    Correct answer: 2 Ω

    The value is (6 × 3) ÷ 9 = 2 Ω.

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  10. A convex lens is also called a:

    • 1 Plane lens
    • 2 Diverging lens
    • 3 Concave lens
    • 4 Converging lens
    Show answer

    Correct answer: Converging lens

    It brings parallel rays together.

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  11. When light passes from air into glass, it bends:

    • 1 Away from the normal
    • 2 Back into the air
    • 3 Toward the normal
    • 4 Not at all
    Show answer

    Correct answer: Toward the normal

    Light slows down in the denser medium and bends toward the normal.

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  12. The weight of a 5 kg body on Earth (g = 10 m/s²) is:

    • 1 50 N
    • 2 0.5 N
    • 3 15 N
    • 4 5 N
    Show answer

    Correct answer: 50 N

    W = mg = 50 N.

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  13. The SI unit of power is the:

    • 1 Newton
    • 2 Pascal
    • 3 Joule
    • 4 Watt
    Show answer

    Correct answer: Watt

    One watt is one joule per second.

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  14. A body starts from rest and accelerates at 2 m/s² over 9 m. Its final speed is:

    • 1 9 m/s
    • 2 6 m/s
    • 3 18 m/s
    • 4 3 m/s
    Show answer

    Correct answer: 6 m/s

    v² = 2as = 36, so v = 6 m/s.

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  15. A machine does 600 J of work in 10 s. Its power is:

    • 1 6000 W
    • 2 6 W
    • 3 610 W
    • 4 60 W
    Show answer

    Correct answer: 60 W

    Power = work ÷ time = 60 W.

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  16. A potential difference of 12 V drives a current of 3 A through a resistor. The resistance is:

    • 1 4 Ω
    • 2 9 Ω
    • 3 36 Ω
    • 4 0.25 Ω
    Show answer

    Correct answer: 4 Ω

    R = V ÷ I = 4 Ω.

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  17. A wave has a frequency of 5 Hz. Its time period is:

    • 1 0.5 s
    • 2 2 s
    • 3 0.2 s
    • 4 5 s
    Show answer

    Correct answer: 0.2 s

    T = 1 ÷ f = 0.2 s.

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  18. A force of 100 N acts on an area of 0.5 m². The pressure is:

    • 1 50 Pa
    • 2 100 Pa
    • 3 200 Pa
    • 4 20 Pa
    Show answer

    Correct answer: 200 Pa

    Pressure = force ÷ area = 200 Pa.

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  19. Which of these cannot travel through a vacuum?

    • 1 Light
    • 2 Radio waves
    • 3 X-rays
    • 4 Sound
    Show answer

    Correct answer: Sound

    Sound needs a medium, and electromagnetic waves do not.

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  20. The two forces in an action and reaction pair of Newton's third law act on:

    • 1 A third body
    • 2 Different bodies
    • 3 The same body
    • 4 The ground only
    Show answer

    Correct answer: Different bodies

    The action acts on one body and the reaction acts on the other.

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  21. A liquid has a density of 800 kg/m³. The mass of 0.5 m³ of it is:

    • 1 400 kg
    • 2 1.6 kg
    • 3 800 kg
    • 4 1600 kg
    Show answer

    Correct answer: 400 kg

    Mass = density × volume = 400 kg.

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  22. A charge of 6 C passes a point in 2 s. The current is:

    • 1 8 A
    • 2 12 A
    • 3 0.33 A
    • 4 3 A
    Show answer

    Correct answer: 3 A

    Current = charge ÷ time = 3 A.

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  23. A concave mirror is also called a:

    • 1 Diverging mirror
    • 2 Convex mirror
    • 3 Converging mirror
    • 4 Plane mirror
    Show answer

    Correct answer: Converging mirror

    It brings parallel rays together.

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  24. After two half-lives, the fraction of a radioactive sample that is left is:

    • 1 1/4
    • 2 1/8
    • 3 1/2
    • 4 0
    Show answer

    Correct answer: 1/4

    Each half-life halves the amount.

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