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

Name two appliances in which an electric motor is used.

In an electric motor the energy transformation is ______.

Draw a ray diagram to show the appearance of a stick partially immersed in water. Explain your answer. 

A fish is looking at a 1.0 m high plant at the edge of the pond. Will the plant appear shorter or taller than its actual height, to the fish. Draw a ray diagram to support your answer. 

The given figure shows a point source P inside a water container. Three rays A, B, and C starting from the source P are shown up to the water surface.

1. Show in the diagram the path of these rays after striking the water. The critical angle for water-air surface is 48°.
2. Name the phenomenon which the rays A, B, and C exhibit. 

Compare the magnitudes of centripetal and centrifugal force.

State two differences between the centripetal and centrifugal force.

A boy experiences a centrifugal force on his hand when he rotates a piece of stone tied at one end of a string, holding the other end in the hand.

The centrifugal force is ______.

Write the lens formula explaining the meaning of the symbols used.

The correct lens formula is ______.

1. At what position a candle of length 3 cm be placed in front of a convex lens so that its image of length 6 cm be obtained on a screen placed at distance 30 cm behind the lens?
2. What is the focal length of lens in part (a)?

A concave lens forms the image of an object kept at a distance 20 cm in front of it, at a distance 10 cm on the side of the object.

1. What is the nature of the image?
2. Find the focal length of the lens.

Where should an object be placed in front of a convex lens of focal length 0.12 m to obtain a real image of size three times the size of the object, on the screen?

A lens forms the image of an object placed at a distance of 45 cm from it on a screen placed at a distance 90 cm on the other side of it. Find:

1. the focal length of lens,
2. the magnification of the image.

What is an electric motor?

Resonance is ______.

Choose the correct relation for e.m.f. (ε) and terminal voltage V:

A convex lens of focal length 10 cm is placed at a distance of 60 cm from a screen. How far from the lens should an object be placed so as to obtain a real image on the screen?

We are able to see the T.V. channels clearly when we set T.V. on auto-tuning.

1. Which phenomemon led to the clear visibility of the channels, due to auto-tuning?
2. Define the above phenomenon mentioned by you.
3. Give any one more example of this phenomenon.