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

The speed of light in air is 3 × 10⁸ ms^-1. Calculate the speed of light in water. The refractive index of water is 4/3.

The velocity of light in diamond is 121000 kms^-1. What is its refractive index?

Write the approximate values of speed of light in (i) air and (ii) glass. Use these values to calculate the refractive index of glass with respect to air.

The refractive index of glass with respect to air is 3/2. What is the refractive index of air with respect to glass?

A glass block is having refractive index 3/2, the light ray is incident at an angle 45°. Find the sine of the angle of, refraction inside the glass block.

A coin placed at the bottom of a beaker appears to be raised by 4.0 cm. If the refractive index of water is 4/3, find the depth of the water in the beaker.

What is meant by ‘MCB’? Which part of the domestic electric circuit does it replace?

The refractive index of glass with respect to air is 1.5. What is the value of the refractive index of air with respect to glass?

What is a switch? State its function in an electric circuit.

What are ‘dual switches’? Mention their one main use.

Why should switches always be connected to the live wire? Give one precaution that should be taken while handling switches.

Define the term Amplitude.

Two astronauts cannot hear each other on the moon. Why?

Explain why does a wine glass starts rattling, when a note of some particular frequency is struck by a piano?

Explain why strings of different thicknesses are provided on a stringed instrument.

Define bound electrons.

Define free electrons.

What do you mean by electron emission?

What are the types of emission?

State two characteristics of the substance used as thermionic emitter.