ICSE ICSE Class 8 - CISCE Question Bank Solutions

The expression of power P is

1 H.P. is equal to

Write true or false 

A virtual image formed by a spherical mirror is always erect and situated behind the mirror.

A ray of light travels from a denser medium to a rarer medium. How will it bend?

A coin placed at the bottom of a vessel appears to be raised when water is poured in the vessel.

What do you mean by the term dispersion?

What is a spherical mirror?

State the two kinds of spherical mirror and distinguish them with the aid of proper diagrams.

Explain the following terms : 
Pole, Centre of curvature, Radius of curvature, Principal axis. Show them on separate diagrams for each of the concave and convex mirrors.

What do you understand by the focus and focal length of a spherical mirror? Show them on the separate diagrams for each of a concave mirror and a convex mirror.

How is a spherical mirror used to converge a beam of light at a point? Name the type of mirror used.

How is a spherical mirror used to diverge a beam of light from a point? Name the type of mirror used.

State the direction of incident ray which after reflection from a spherical mirror gets reflected along its own path. Give a reason.

How is the focal length of a spherical mirror related to its radius

A pump raises water by spending 4×10⁵J of energy in 10s. Find the power of the pump.

It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the work done .

Which are the two convenient rays that are chosen to construct the image by a spherical mirror for a given object? Explain with the help of suitable ray diagrams.

It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the power spent by then.

Draw separate diagram for the formation of virtual image of an object by a concave mirror.

State the kind of mirror used
(a) by a dentist, and
(b) as a street light reflector.