Question

define power of lens and write its SI unit name the type of lens which has a negative power calculate the power of concave lens whose principal focus is the distance of 50 cm from its optical centre ​

Answer 1

Answer:

1) The Power of Lens is said to be 1 Dioptre whose Focal Length is 1 Metre.

P = 1/f(in metres)

2) It's SI unit is Dioptre (D).

3) Concave Lens has Negative Power since it's Focal Length is Negative.

4) Power = 1/f(in metres)

= 100/50

= 2 D

Explanation:

Answer 2

Answer:

Power of a lens is the degree of convergence or divergence of light ray achieved by a lens.

SI UNIT: Dioptre denoted by D

Concave lens has a negative power

Given

f = 50cm

Solution

p = 100/f

= -100/f

= -100/50

= -2D

Hope it helps..