Question

1.Answer following questions (1 - 4). Each question carries 2 marks. (2 x 4 = 8)


1 Find the number of images formed by two plane mirrors when kept at (i) 32, (ii) 60, (iii) 75 and (iv) 90 degrees between them when an object is kept symmetrically between them.


2 What is spherical aberration ? How can it be rectified?


3 What is dispersion of light? Why light undergoes dispersion?


4 A monkey on a tree top 8m above ground sees a tortoise under water . It appears to be 7 cm below water surface. What is the actual position of the tortoise under water?

How much above the water will the monkey appears for the tortoise?

Refractive index of water is 4/3.

2.Answer any one of the following questions. (3 x 1 = 3)Define Angular magnification or

magnifying power of a Compound Microscope. (1mark)

Draw a neat labelled diagram showing image formation in a compound microscope when the final image is formed at D. (2 marks)


OR


Define angular dispersion. (1 mark)

Find the angular dispersion between red and violet colours produced by a flint glass prism of refracting angle 60 degrees. Refractive indices of prism for red and violet colours are 1.622 and 1.663 respectively.


3.Answer any one of the following questions. (4 x 1 = 4)


A spherical surface separates two transparent media. Derive an expression that relates object and image distances with radius of curvature of the surface for a point object. State the assumptions taken. Draw necessary diagram.


OR


Derive lens maker's equation. Why is it called so?

Draw neat labelled diagram.

Answer 1

Answer:

draw neat labelled diagram

Answer 2

Answer:

n = 8

n = 360 / 0 - 1

n + 1 = 360 / 0

( 8 + 1 ) = 360 / 0

:. 0 = 360 / 9 =40

0 = 40 .

Explanation: