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

State the condition for the following a lens has both its focal lengths equal .

State the condition for the following  a ray passes undeviated through the lens .

If the angle of incidence is greater than the critical angle, light is not refracted at all, when it falls on the surface from a denser medium to a rarer medium.

How is the power of a lens related to its focal length?

How does the power of a lens change if its focal length is doubled?

How is the sign (+ or -) of power of a lens related to its divergent or convergent action?

On reducing the focal length of a lens, its power ______.

The power of a lens is + 1.0 D is : 

Express the power (with sign) of a concave lens of focal length 20 cm.

What do you understand by the conservation of mechanical energy?

A body of mass 10 Kg is kept at a height of 5m. It is allowed to fall and reach the ground.
(i) What is the total mechanical energy possessed by the body at the height of 2m assuming it is a frictionless medium ?
(ii) What is the kinetic energy possessed by the body just before hitting the ground ? Take g = 10 m/s².  

How is accommodation produced?

Is it practically possible to convert a form of energy completely into the other useful form? Explain your answer.

What is degraded energy?

Explain the degradation of energy by taking one example of your daily life.

The conversion of part of energy into an undesirable form is called ______.

Which lens has more power a thick lens or a thin lens?

The power of a lens is +2.0 D. Find its focal length and state the kind of lens.