Question

Find the nature and power of lens which forms a real and inverted image of magnification -1 at a distance of 40cm from its optical centre?

Answer 1

Answer:

Use these formulas to find the answer:

$power = \frac{1}{f}$

$m = \frac{h2}{h1}$

Answer 2

Answer:

it is a convex lens with focal length 20cm

Explanation:

given

magnification is -1

u=-40cm

v/u=m

-1=v/40

v=-40cm

f=20 [object is at 2f1]

p=1/20= 5d

power of lens is 5D