The focal length of a combination of lenses f | vedclass

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(D) The power of a combination of thin lenses in contact is given by the algebraic sum of their individual powers: $P = P_1 + P_2$. Given $P_1 = +2.50

Vedclass · Accepted Answer

$-80$

Vedclass · Answer

(D) The power of a combination of thin lenses in contact is given by the algebraic sum of their individual powers: $P = P_1 + P_2$. Given $P_1 = +2.50 \ D$ and $P_2 = -3.75 \ D$. Therefore,the total power $P = 2.50 \ D + (-3.75 \ D) = -1.25 \ D$. The focal length $f$ in centimeters is given by the formula $f = \frac{100}{P}$. Substituting the value of $P$: $f = \frac{100}{-1.25} = -80 \ cm$. Thus,the focal length of the combination is $-80 \ cm$.

The focal length of a combination of lenses formed with lenses having powers of $+2.50 \ D$ and $-3.75 \ D$ will be .... $cm$.

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