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

1 kWh = ______ J.

A man spends 7.4 kJ energy in displacing a body by 74 m in the direction in which he applies force, in 2.5 s. Calculate the power spent (in H.P) by the man.

A pump is used to lift 600 kg of water from a depth of 75 m in 10s. Calculate:

1. The work done by the pump,
2. the power at which the pump works, and
3. The power rating of the pump if its efficiency is 40%. (Take g = 10m s^-2).

`["Hint" : "Efficiency" = "useful power"/"power input"]`

It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s. Compare the power developed by the persons A and B.

A man raises a box of mass 50 kg to a height of 2 m in 20s, while another man raises the same box to the same height in 50s. Calculated:

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

A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes. Compare:

1. the work, and
2. power developed by them.

A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes.

How much work each does? Take density of water = 10³ kg m^-3 and g = 9.8 N kg^-1.

An obliquely incident light ray bends at the surface due to a change in speed when passing from one medium to another. The ray does not bend when it is incident normally. Will the ray have a different speed in the other medium?

Compare the speeds of light of wavelength 4000 Å (i.e. violet light) and 8000 Å (i.e. red light) in vacuum.

State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.

Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.

Name the radiation which can be detected by thermopile.

Higher the current rating, _______ is the fuse wire.

How does the thickness of a fuse wire depend on its current rating?

The rating of a fuse connected in the lighting circuit is ______.

To which regions of the electromagnetic spectrum do the following wavelengths belong: 
(a) 250 nm 
(b) 1500 nm 

Calculate the shortest wavelength of electromagnetic radiation present in Balmer series of hydrogen spectrum.

State and define the unit of force in the S.I. system.

How is 1 kgf related to the SI unit of force?

What is the work done by the gravitational force on the moon that revolves around the earth?