Optics Question 582

Question: Two lenses of power +12 and - 2 diopters are placed in contact. What will the focal length of combination

[MP PET 1990; MNR 1987; MH CET (Med.) 2001; UPSEAT 2000; Pb. PMT 2003]

Options:

A) 10 cm

B) 12.5 cm

C) 16.6 cm

D) 8.33 cm

Show Answer

Answer:

Correct Answer: A

Solution:

Power of the combination $ P=P _{1}+P _{2} $

$ =12-2=10D $

Focal length of the combination $ F=\frac{100}{P}=\frac{100}{10}=10cm $



NCERT Chapter Video Solution

Dual Pane