Question

please help me...physics class 10 chapter 10 .....answer in detail​

Answer 1

Answer: 1)Power of a lens is defined as the inverse of focal length (in meters) of the lens. It is a measure of the amount of deviation of light ray produced by a lens, more the power, more is the deviation. Unit of power is Dioptre (D).

Explanation:

2)   F = 20.  according to sign coventio  

Ho = 6cm    

V = -15.  

 [As we know  Image formed by concave Mirror is Virtual]

 APPLYING LENS FORMULA  

1/F = -1/U+1/V

 Put values and solve that  will get you the answer.    

M = Hi / Ho = V/U  

 [ Hi= height of Image and Ho is height of object]  

Hi/ Ho = V/U  1\v -1\u = 1\f

1\15 - 1\u = 1\20

1\u = 1\15- 1\20

1\u = 1\60  I\O = V\U

I = 15 × 6 \ 60

I = 1.5 cm