Physics Class 9th
MCQs: Choose the right option.
1. An interval of 200 µs is equivalent to:
(a) 0.01 S (b) 0.02 s (c) 2×10-4 s(d) 2×10-6 s
2. A car starts from rest. Its velocity becomes 20 ms-1 in 8 find its acceleration:
(a) 2.5 ms-2 (b) 2.6 ms-2 (c) 2.7 ms-1 (d) 3.2 ms-1
3. A force that keeps a body to move in circle:
(a) Friction (b) Circular motion (c) Centripetal force (d) Motion
4. The number of perpendicular components of a force are:
(a) 1 (b) 2 (c) 3 (d) 4
5. A polar satellite is launched at 850 km above earth. Find its orbital speed:
(a) 4567 ms-1 (b) 7431 ms-1 (c) 0.17 ms-2 (d) 7431 ms-1
6. A Solar cell is also called:
(a) Solar house (b) Photo cell (c) Solar power (d) Collector
7. When a force acting on a body moves it in the direction of the force:
(a) Joule (b) Force (c) Work (d) Kinetic energy
8. Calculate power of a pump which can lift 200 kg of water through a height 6m in 10 s:
(a) 1200 watts (b) 345 watts (c) 12.00 watts (d) 100 watts
9. The density of air is 1.3 kgm-3 Find the mass of air in a room measuring 8m×5m×4m:
(a) 209 kg (b) 208 kg (c) 208 g (d) 345 g
10. Which of the following material has large specific heat:
(a) Copper (b) Ice (c) Water (d) Mercury
11. Which is a poor conductor of heat:
(a) Wool (b) Glass (c) Water (d) Feathers
12. Land & sea breezes are also the example of:
(a) Conduction (b) Radiation (c) Convection (d) Heat
i. Difference between Atomic physics & Nuclear physics?
ii. Differences b/w Base & Derived quantities?
iii. Why do we need to measure extremely small interval of times?
iv. Difference b/w Rest & Motion?
v. Why vector quantities cannot be added & subtracted like scalar quantities?
vi. Define Linear & Random motion?
vii. What is inertia& field force?
viii. Describe ways to reduce friction?
ix. When a gun is fired it recoils why? Define speed & velocity.
i. What is Centre of gravity& Centre of mass?
ii. Explain the first condition for equilibrium?
iii. Why law of gravitation is important for us?
iv. Why does the value of g vary from place to place?
v. Why communication satellites are stationed at geostationary orbits?
vi. Define K.E. & derive its relation?
vii. Name the five devices that convert electrical energy into mechanical energy?
viii. State Pascal’s law & Archimedes Principle?
i. What is up thrust? Explain the process of floatation?
ii. What is Hooke’s law? What is meant by elastic limit?
iii. Define the term heat & Temperature?
iv. Define specific heat. How would you find the specific heat of a solid?
v. Define latent heat of fusion & vaporization?
vi. Why metals are good conductors of heat?
vii. What is meant by Convection current?
viii. How various surfaces can be compared by a Leslie cube?
1. (a) Explain the Second & Third equation of motion?
(b) Your hair grow at the rate of 1mm per day. Find their growth rate in nms-1 ?
2. (a) Explain the Force & Momentum & Newton’s Second law of Motion?
(b) Find the acceleration produced by a force of 100 N in a mass of 50 kg.
3. (a) Describe the Conditions for Equilibrium & Mass of Earth?
(b) Calculate the value of g at a height of 3600 km above the surface of the earth?
4. (a) Describe the forms of energy & Kinetic energy?
(b) Normal human body temperature is 98.60 F convert it into Celsius scale & Kelvin scale.
5. (a) Describe the Pascal’s Law & Hooke’s law?
(b) The head of a pin is a square side 10 mm. Find the pressure on it due to a force of 20 N?
