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

Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.

Name the two waves. compare the speeds of these waves when they travel in vacuum.

The above table shows different parts of the electromagnetic spectrum.
(a)    Identify the parts of the spectrum marked as A, B, C and D.
(b)    Which of the radiations A or B has the higher frequency?
(c)    State two properties which are common to all parts of the electromagnetic spectrum.
(d)    Name one source of each of the radiation of electromagnetic spectrum.
(e)    Name one detector for each of the radiation.
(f)    Name one use of each of the radiation.

1. 1. Calculate the speed of the wave.
   2. Name the medium through which it is traveling.

In equilibrium algebraic sum of moments of all forces about the point of rotation is ______.

The moon revolving around the earth is in ______ equilibrium.

In figure, a uniform bar of length l m is supported at its ends and loaded by a weight W kgf at its middle. In equilibrium, find the reactions R₁ and R₂ at the ends. 

`["Hint:"  "In equilibrium"  "R"_1 + "R"_2 = "W"   "and"   "R"_1 xx l/2 = "R"_2 xx l/2]`

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

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.