In an experiment with a convex lens, The plot of the image distance $\left(v^{\prime}\right)$ against the object distance ($\left.\mu^{\prime}\right)$ measured from the focus gives a curve $v^{\prime} \mu^{\prime}=225$. If all the distances are measured in $\mathrm{cm}$. The magnitude of the focal length of the lens is ___________ cm.
Answer (integer)
15
Solution
<p>Using Newton's formula for lenses,</p>
<p>$v'\mu ' = {f^2} = 225 \Rightarrow f = 15$</p>
About this question
Subject: Physics · Chapter: Optics · Topic: Lenses and Optical Instruments
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