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

State four ways in which machines are useful to us.

Name a machine to multiply force ?

Name a machine to change the point of application of force ?

In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.

Express joule in terms of erg.

1 J = ______ calorie.

Differentiate between energy and power.

A boy of mass 40 kg climbs up the stairs and reaches the roof at a height 8 m in 5 s. Calculate:

1. the force of gravity acting on the boy,
2. the work done by him against the force of gravity,
3. the power spent by boy. (Take g = 10 m s^-2)

It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B does the same in 15 s. Compare the work done.

A weight lifter lifted a load of 200 kgf to a height of 2.5 m in 5 s. Calculate:

1. the work done, and
2. the power developed by him. Take g = 10 N kg^-1

A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:

1. energy spent by machine,
2. power at which the machine works.

A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:

1. the work done, and
2. the power developed by them. Take g = 10 N kg^-1.

A water pump raises 50 litres of water through a height of 25 m in 5 s. Calculate the power of the pump required.

(Take g = 10 N kg^-1 and density of water = 1000 kg m^-3)

Name the forms of energy which a wound-up watch spring possesses.

Name three factors on which the deviation produced by a prism depends and state how does it depend on the factors stated by you.

How does the deviation produced by a triangular prism depend on the colours (or wavelengths) of light incident on it?

Which colour of white light travels fastest in glass?

In following figure  shows a thin beam of white light from a source S striking on one face of a prism.

Complete the diagram to show effect of prism on the beam and to show what is seen on the screen.

In following diagram shows a thin beam of white light from a source S striking on one face of a prism.

A slit is placed in between the prism and the screen to pass only the light of green colour. What will you then observe on the screen?

In following diagram  shows a thin beam of white light from a source S striking on one face of a prism.

 What conclusion do you draw from the observation in part (b) above?