Q 12-09-029NEETJEE MainEasy
A convex lens of focal length $25$ cm and a concave lens of focal length $50$ cm are placed in contact. The power of the combination is
Answer: (D) $+2$ D
$P = \dfrac{100}{25} - \dfrac{100}{50} = 4 - 2 = +2$ D (converging, $f = 50$ cm).
Solution by Sreeraj P, M.Sc Physics