Question

a cancave lens of focal length 25 cm and a convex lens of focal length 20 CM are placed in contact with each other what is the power of this combination also calculate focal length of this combination​

Answer 1

Answer:

f1=-25cm= -0.25m

f2=20cm= 0.20m

p=1/f1+1/f2

p= -4+5

p=1D

1/f = 1/f1+1/f2

1/f = 1

f= 1m

Answer 2

Answer:in respect of convex lens F=F is indirectly proportional to (bending )and in respect of concave lens F is indirectly proportional to (diversing)

Explanation: