Physics XI
Grade XI Question Bank
Question Collection
Mechanics
Kinematics
Laws of Motion
- 1. State Newton’s Second Law of Motion.
- 2. If action and reaction are always equal and opposite, why don’t they always cancel each other?
- 3. Explain why a cricketer moves his hands backwards while catching ball?
- 4. The leaves fall when a tree is shaken. Give reason.
- 5. Why is it difficult to run fast on sand?
- 6. If a moving bullet striking a block of wood on a frictionless table embeds inside it what happens to the KE of the bullet?
- 7. Is friction a necessary evil? Explain.
- 8. Why do we slip on a rainy day?
- 9. Can a body be regarded in a state of rest as well as in motion at the same time? Give an example.
- 10. Explain how Newton’s first law of motion follows from the second law.
Work and Energy
- 1. In a siphon, water is lifted above its original level during its flow from one container to another, where does it get the needed potential energy from?
- 2. What is meant by elastic and inelastic collision?
- 3. Differentiate between conservation of kinetic energy and conservation of linear momentum.
- 4. Distinguish between conservative and non-conservative force.
- 5. How does K.E. of an object change if its momentum is doubled?
- 6. “The earth moving round the sun in an orbit is acted upon by a force; hence the work must be done on the earth by this force.” Do you agree with this statement?
Circular Motion
- 1. When a bus takes a turn, passengers are thrown away from the centre of the curved path. Why?
- 2. A solid tied at the end of a string is revolved in vertical. At what point the tension in the string will be the greatest?
- 3. Explain why a cyclist bend while going along curved road?
- 4. Why are roads banked on curved path?
Gravitation
- 1. What will happen to the value of ‘g’ if the earth stops rotating?
- 3. The weight of a body is less inside the earth than on the surface. Explain.
- 4. Why an astronaut in a space capsule orbiting the earth experiences a feeling of weightlessness?
- 5. How does ‘g’ at a point vary with distance from the centre of the earth? Where is the highest value of ‘g’? Explain.
- 6. Explain why the moon has no atmosphere?
- 7. What do you mean by geo-stationary satellite? Explain?
- 8. If the sun somehow collapsed to form a black hole, what effect would this event have on the orbit of the earth?
Equilibrium
- 1. Is it possible for a solid body to have no matter at it centre of gravity?
- 2. What is the difference between centre of gravity and centre of mass of a system?
- 3. Why is a cow more stable than a man?
- 5. What is meant by the moment of a couple?
- 6. Can a body be in equilibrium if it is in motion? Explain.
- 7. Why is a horse more stable than a man?
- 8. A man carrying a bucket of water on his hand always leans to the opposite side. Explain.
- 9. Why a wrench of longer arm is preferred in comparison to a wrench of short arm?
- 10. Explain why a man carrying a load on his back leans forward?
- 11. During pregnancy, woman often develop back pains from leaning backward while walking. Why do they have to walk this way?
Rotational Dynamics
- 2. A fan with blades takes longer time to come to rest than without the blades. Why?
- 3. If the earth is struck by meteorites, the earth will slow down slightly. Why?
- 4. Suppose that only two external forces act on a rigid body and the two forces are equal in magnitude but opposite in direction. Under what conditions will the body rotate?
- 5. What is the counterpart of the mass and force in rotational motion?
- 6. Explain why spokes are fitted in the cycle wheel.
- 7. A dancer girl is rotating over a turntable with her arms outstretched. If she lowers her arms how does this affect her motion?
Elasticity
- 1. A rigid, lighter than air balloon filled with Helium cannot continue to rise indefinitely. Why?
- 2. Why bridges are declared unsafe after a long use?
- 3. Explain which one is more elastic- rubber or steel.
Periodic Motion (Simple Harmonic Motion)
- 1. If a pendulum clock is taken to a mountain top, does it gain or lose time?
- 3. On what factors does the time period of a simple pendulum depend?
- 4. What are the drawbacks of simple pendulum?
- 5. A pendulum clock is taken to moon. Will it gain or lose time?
- 7. A body is moving in a circular path with constant speed. Is this motion a simple harmonic?
Fluid Static
- 1. Why does ice float in water?
- 2. Why is the bottom of a ship made heavy?
- 3. Steel balls sink in water but they don’t sink in mercury. Why?
- 4. Does a ship sink more in river water or in sea water? Explain.
- 6. State the laws of flotation.
- 7. What are centre of buoyancy and metacentre?
- 9. Why is easier to lift a body in a liquid than in air?
- 10. A helium filled balloon rises to a certain height and then halts. Why?
- 11. A cork is floating in water. What is the apparent weight of the cork?
- 12. How will you make difference between density and specific gravity of a body?
