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संबंधित प्रश्न
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
State two disadvantages of producing hydroelectricity.
What do you mean by degradation of energy?
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
How much work is done when a force of 1 N moves a body through a distance of 1 m in its own direction?
Define the term 'work'. Write the formula for the work done on a body when a force acts on the body in the direction of its displacement. Give the meaning of each symbol which occurs in the formula.
What should be the angle between the direction of force and the direction of motion of a body so that the work done is zero?
Ravi applied a force of 10 N and moved a book 30 cm in the direction of the force. How much was the work done by Ravi?
What is the SI unit of work?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
A bucketful of water is to be drawn from a well ______ will be done when a ______ is applied to do this because there will be a ______ of water.
(displacement, work, force)
A force can cause an object to change its ______.
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
