(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

What do you mean by an equilibrium of a body?

State the condition when a body is in static equilibrium.

State the condition when a body is in dynamic equilibrium.

State two condition for a body acted upon by several forces to be in equilibrium.

State the principle of moments. Give one device as an application of it

The figure shows a uniform metre rule placed on a fulcrum at its mid-point O and having a weight 40 gf at the 10 cm mark and a weight of 20 gf at the 90 cm mark.

1. Is the metre rule in equilibrium? If not how will the rule turn?
2. How can the rule be brought in equilibrium by using an additional weight of 40 gf?

State the condition when the work done by a force is positive.  Explain with the help of examples.

A body is moved in a direction opposite to the direction of force acting on it. State whether the work is done by the force or work is done against the force

When a body moves in a circular path, how much work is done by the body? Give reason.

(Hint: The body is acted upon by the centripetal force.)

A satellite revolves around the earth in a circular orbit. What is the work done by the force of gravity? Give reason.

A coolie X Carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head move the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.

The work done by a fielder when he takes a catch in a cricket match, is negative. Explain.

Give an example when work done by the force of gravity acting on a body is zero even though the body gets displaced from its initial position.

A light ray passes from water to

1. air, and
2. glass.

In each case, state how does the speed of light change.

What are the S.I. and C.G.S units of work? How are they related? Establish the relationship.

State and define the S.I. unit of work.

What physical quantity does the electron volt (eV) measure? How is it related to the S.I. unit of that quality?

How is kilowatt hour related to joule?

State two factors on which power spent by a source depends. Explain your answer with examples.

Differentiate between work and power.