A) Converging and of focal length 10 cm
B) Converging and of focal length 20 cm
C) Converging and of focal length 40 cm
D) Diverging and of focal length 20 cm
Correct Answer: A
Solution :
[a] A diverging lens is ruled out because both x and y are positive values. Both x and y equal 20 cm at their smallest sum, which occurs when \[x+y=40cm=4f\] \[\therefore f=10cm\] This indicates a converging lens of focal length=10cmYou need to login to perform this action.
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