Subject physics

Written by Dr. Hamza Farooq (Physics)

COMSATS · طبیعیات · 24 سوالات

نام: ____________________ تاریخ: ____________

The SI unit of energy is the:
- A Watt
- B Newton
- C Pascal
- D Joule
A force acts on a 5 kg body and gives it an acceleration of 2 m/s². The force is:
- A 10 N
- B 3 N
- C 2.5 N
- D 7 N
A body with an initial speed of 5 m/s accelerates at 2 m/s² for 3 s. Its final speed is:
- A 11 m/s
- B 6 m/s
- C 15 m/s
- D 30 m/s
A current of 2 A flows in a 6 Ω resistor. The potential difference is:
- A 12 V
- B 3 V
- C 0.33 V
- D 8 V
The kinetic energy of a 2 kg body at 3 m/s is:
- A 18 J
- B 3 J
- C 9 J
- D 6 J
A force of 20 N moves a body 3 m in its own direction. The work done is:
- A 17 J
- B 60 J
- C 6.7 J
- D 23 J
A wave has a time period of 0.5 s. Its frequency is:
- A 1 Hz
- B 5 Hz
- C 0.5 Hz
- D 2 Hz
Which of these is a scalar quantity?
- A Velocity
- B Force
- C Displacement
- D Speed
Resistors of 6 Ω and 3 Ω are connected in parallel. The equivalent resistance is:
- A 2 Ω
- B 18 Ω
- C 4.5 Ω
- D 9 Ω
A convex lens is also called a:
- A Plane lens
- B Diverging lens
- C Concave lens
- D Converging lens
When light passes from air into glass, it bends:
- A Away from the normal
- B Back into the air
- C Toward the normal
- D Not at all
The weight of a 5 kg body on Earth (g = 10 m/s²) is:
- A 50 N
- B 0.5 N
- C 15 N
- D 5 N
The SI unit of power is the:
- A Newton
- B Pascal
- C Joule
- D Watt
A body starts from rest and accelerates at 2 m/s² over 9 m. Its final speed is:
- A 9 m/s
- B 6 m/s
- C 18 m/s
- D 3 m/s
A machine does 600 J of work in 10 s. Its power is:
- A 6000 W
- B 6 W
- C 610 W
- D 60 W
A potential difference of 12 V drives a current of 3 A through a resistor. The resistance is:
- A 4 Ω
- B 9 Ω
- C 36 Ω
- D 0.25 Ω
A wave has a frequency of 5 Hz. Its time period is:
- A 0.5 s
- B 2 s
- C 0.2 s
- D 5 s
A force of 100 N acts on an area of 0.5 m². The pressure is:
- A 50 Pa
- B 100 Pa
- C 200 Pa
- D 20 Pa
Which of these cannot travel through a vacuum?
- A Light
- B Radio waves
- C X-rays
- D Sound
The two forces in an action and reaction pair of Newton's third law act on:
- A A third body
- B Different bodies
- C The same body
- D The ground only
A liquid has a density of 800 kg/m³. The mass of 0.5 m³ of it is:
- A 400 kg
- B 1.6 kg
- C 800 kg
- D 1600 kg
A charge of 6 C passes a point in 2 s. The current is:
- A 8 A
- B 12 A
- C 0.33 A
- D 3 A
A concave mirror is also called a:
- A Diverging mirror
- B Convex mirror
- C Converging mirror
- D Plane mirror
After two half-lives, the fraction of a radioactive sample that is left is:
- A 1/4
- B 1/8
- C 1/2
- D 0

جوابی کلید

1. D, 2. A, 3. A, 4. A, 5. C, 6. B, 7. D, 8. D, 9. A, 10. D, 11. C, 12. A, 13. D, 14. B, 15. D, 16. A, 17. C, 18. C, 19. D, 20. B, 21. A, 22. D, 23. C, 24. A

Energy is measured in joules.
F = ma = 5 × 2 = 10 N.
v = u + at = 5 + 6 = 11 m/s.
V = IR = 2 × 6 = 12 V.
KE = ½ × 2 × 9 = 9 J.
W = Fd = 60 J.
f = 1 ÷ T = 2 Hz.
Speed has magnitude only.
The value is (6 × 3) ÷ 9 = 2 Ω.
It brings parallel rays together.
Light slows down in the denser medium and bends toward the normal.
W = mg = 50 N.
One watt is one joule per second.
v² = 2as = 36, so v = 6 m/s.
Power = work ÷ time = 60 W.
R = V ÷ I = 4 Ω.
T = 1 ÷ f = 0.2 s.
Pressure = force ÷ area = 200 Pa.
Sound needs a medium, and electromagnetic waves do not.
The action acts on one body and the reaction acts on the other.
Mass = density × volume = 400 kg.
Current = charge ÷ time = 3 A.
It brings parallel rays together.
Each half-life halves the amount.