# Light| Worksheet Solutions| Class 7

Worksheet solutions for chapter: Light for class 7 are provided below.

(1) How will you identify convex lens and concave lens?

Ans-

Concave lenses are thinner in the middle than at the edges. These are diverging lenses. Convex lenses are thicker in the middle than at the edges. These are converging lenses. (2) Give two uses of concave mirror.

Ans-

Two uses of concave mirror are given below-

(i) These mirrors are used in applying makeup and in shaving mirrors.

(ii)These mirrors are used in reflecting telescope.

(3) Give characteristics of image of an object formed by a convex mirror.

Ans-

Characteristics of image of an object formed by a convex mirror is given below-

(i) Smaller than the object

(ii)Erect

(iii) Virtual

(4) Give two differences of image formed by concave and convex mirror.

Ans-

Two differences of images formed by concave and convex mirror

 SN Concave Mirror Convex Mirror 1. Larger than object Smaller than object 2. Real Virtual

(5) Which lens/mirror is used in giving things-

(i) Magnifying lens

(ii) Makeup

(iii) Side view mirror

(iv) Binocular

Ans-

 SN Items Mirror/lens used (i) Magnifying glass Convex lens (ii) Makeup Concave mirror (iii) Side view mirror Convex mirror (iv) Binocular Concave lens

(6) What do you understand by erect? Which mirrors/lenses give erect image?

Ans-

An upright image of an object is called erect image. Plane mirror, Convex mirror, concave lens give erect image of an object.

(7) Fill in the blanks:

(i)A plane mirror give always …….. Image.

(ii) ………. image can be formed on screen.

(iii)A rainbow has ……… colours.

Ans-

(i)A plane mirror gives always virtual Image.

(ii) Real image can be formed on screen.

(iii)A rainbow has seven colours.

(8) Name the colours of white light.

Ans- Seven colours of white light are red, orange yellow, green, blue, indigo and violet.

(9) Can water act as a mirror? Give an example in favour of your answer.

Ans- Yes, water can act as a mirror. Reflection of objects can be seen in water. It can only happen if water act as a mirror and change the direction of light.

(10) Does light travel along straight line? Give proof in support of your answer.

Ans-

Yes, light travels along straight line.

Proof-

Take a candle and lighten it. Take a straight pipe and try to see candle through it.

Result- you can see the light. Take a bent pipe and try to see candle flame through bent pipe.

Result- You can not see candle flame through bent pipe.

It shows light travels in straight line. Helping Topics

Light

NCERT Solutions Class 7