A convex lens of power +6 D is placed in cont | vedclass

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(B) When two thin lenses are placed in contact,the equivalent power $P$ of the combination is given by the algebraic sum of the individual powers: $P

Vedclass · Accepted Answer

Convex,$50 cm$

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(B) When two thin lenses are placed in contact,the equivalent power $P$ of the combination is given by the algebraic sum of the individual powers: $P = P_1 + P_2$.Given $P_1 = +6 D$ and $P_2 = -4 D$.Therefore,$P = +6 D + (-4 D) = +2 D$.Since the equivalent power $P$ is positive,the combination behaves as a convex lens.The focal length $f$ is given by $f = \frac{1}{P}$ (in meters) or $f = \frac{100}{P}$ (in cm).$f = \frac{100}{2} = +50 cm$.Thus,the combination is a convex lens with a focal length of $50 cm$.

$A$ convex lens of power $+6 D$ is placed in contact with a concave lens of power $-4 D$. What is the nature and focal length of the combination?

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