lens and power

Asked by nishac | 28th Dec, 2009, 11:35: AM

Expert Answer:

Focal length of convex lens, f1 = 18 cm = 0.18 m

Power of convex lens , P1 = 5.6 D

Focal length of concave lens, f2 = - 24 cm = - 0.24 m

Power of concave lens, P2 = - 4.2 D

Power of the combination, P = P1 + P2 = 5.6 - 4.2 = 1.4 D

Focal length of the combination , F = 1 / 1.4 = 0.7 m

Hence, the combination will act as convex lens.

Answered by  | 4th Jan, 2010, 10:18: PM

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