Question

find the focal length of a
convex lens
which produce
real image
at 60 cm from the lens
when
object is placed at
40cm
front
of the lens
​

Answer 1

Answer:

24cm...

Explanation:

According to sign convention :

Image distance (V) = 60cm

Object distance (U) = -40cm

Focal length. (F) = ?

Lens formula:

• 1/F = 1/V - 1/U

= 1/F = 1/60 - 1/-40

= 1/F = 1/60 + 1/40

= 1/F = 2+3/120

= 1/F = 5/120

= 5F = 120

= F = 120/5 = 24

= F= 24cm

°°°Focal length = 24cm...