Advertisements
Advertisements
Explain with the help of a diagram of how fish is able to see the objects above it.
Concept: undefined >> undefined
Draw a diagram of a prism and label:
(i) the base,
(ii) the refracting surfaces,
(iii) the refracting edge,
(iv) the refracting angle in it.
Concept: undefined >> undefined
Advertisements
Calculate the velocity of light in a glass block of refractive index 1.5. (Velocity of light in air = 3 × 108 m/s)

Concept: undefined >> undefined
How should the electric lamps in a house be connected so that the switching ON or OFF in a room has no effect on other lamps in the same building?
Concept: undefined >> undefined
A ray of light PQ is incident normally on the hypotenuse of a right-angled prism ABC as shown in the diagram given below:

(i) Copy the diagram and complete the path of the ray PQ till it emerges from the prism.
(ii) What is the value of the angle of deviation of the ray?
(iii) Name an instrument where this action of the prism is used.
Concept: undefined >> undefined
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.
Concept: undefined >> undefined
The velocity of light in diamond is 121000 kms-1. What is its refractive index?
Concept: undefined >> undefined
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.
Concept: undefined >> undefined
The refractive index of glass with respect to air is 3/2. What is the refractive index of air with respect to glass?
Concept: undefined >> undefined
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.
Concept: undefined >> undefined
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.
Concept: undefined >> undefined
What is meant by ‘MCB’? Which part of the domestic electric circuit does it replace?
Concept: undefined >> undefined
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?
Concept: undefined >> undefined
What is a switch? State its function in an electric circuit.
Concept: undefined >> undefined
What are ‘dual switches’? Mention their one main use.
Concept: undefined >> undefined
Why should switches always be connected to the live wire? Give one precaution that should be taken while handling switches.
Concept: undefined >> undefined
Two astronauts cannot hear each other on the moon. Why?
Concept: undefined >> undefined
Explain why does a wine glass starts rattling, when a note of some particular frequency is struck by a piano?
Concept: undefined >> undefined
Explain why strings of different thicknesses are provided on a stringed instrument.
Concept: undefined >> undefined
