Question

the power of septacal lens of 2 daiopeter the focal length will be​

Answer 1

power of lens=1/focal length

=2=1/f

=2f=1

=f=1/2

=f=0.5cm

Answer 2

P = 1/f

where f is focal length

P = 2D

2 = 1/f

f = 1/2

f = 0.5 m

Remember: take focal length in m.

If Focal length is given in cm and you need to find the Power then

P = 100/f....

Thank you