Questions
Work done by the potential energy of the object, which is above the ground is not ______________.
- directly proportional to the height from the ground
- directly proportional to the mass of the object
- inversely proportional to the height from the ground
- directly proportional to the gravitational force
- measured in joules
The force by which an object attracts other object is directly proportional to the product of their masses, is ___________________.
- the frictional force
- the gravitational force
- the magnetic force
- the thrust
- the pressure
Which of the following statements is false regarding the gravitational force?
- The planets revolve around the Sun in uniform motion due to presence of gravitational force.
- There is presence of atmosphere on the earth due to gravitational force.
- Tides in seas and oceans are due to gravitational force.
- It keeps the moon in orbit around the earth.
- None of these
How does the gravitational force vary with the nature or properties of the medium in which the masses are placed?
- It remains constant
- It increases in a denser medium
- It decreases in a denser medium
- It becomes zero in rarer medium
- It becomes zero in denser medium
If the displacement is perpendicular to the direction of the force, work done is ___________.
- positive
- negative
- zero
- can be either of three above options
- work cannot be done
When is the work done said to be positive?
- If the body is displaced in the same direction of force.
- If the body is displaced and returns to same point.
- If the body is displaced in the opposite direction of force.
- If the body is not displaced.
- If the body is displaced, irrespective of the direction of force.
Which of the following object /s possess kinetic energy?
(a) Bullet fired from a gun
(b) Weight kept at a height
(c) Hammer striking a nail
(d) Water in an overhead reservoir
- Both a and c
- Both b and d
- Only a
- Only c
- Only d
Which of the following is true about free fall?
- Object falls under the influence of gravity.
- Fall of parachute towards Earth.
- Free fall is independent of the mass of object falling.
- Option 1 and 2.
- Option 1 and 3.
A ball is falling down from a height of 20 cm. What type of energy will it possess, when it will be at 12 cm?
- Potential energy
- Kinetic energy
- Both kinetic energy and potential energy
- It is a free fall so energy will be zero. Hence, there will be no energy
- It is a free fall so energy will be equal to gravity. Hence, gravitational energy
An object weighs W, when on earth. What will be its weight , when on the moon?
- Same
- Six times W
- 1 / 6 times of W
- Zero
- Will depend on the material of the object
An object has M mass, when on earth. What will be its mass, when on moon?
- Same
- Less than M
- More than M
- Zero
- Will vary with the material it is made up of
What will be the mechanical energy of an object, if it has momentum equal to zero?
- Zero
- Equal to its kinetic energy
- Equal to its potential energy
- greater than potential energy.
- None of these
Which of the following object does not possess potential energy?
- A roller coaster on the top of a hill track.
- A rocket ready for takeoff.
- Boiling of liquid nitrogen.
- A lady resting on bed.
- A snowball on top of a snowy mountain.