Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsRefraction at curved surface/LensEasy2 minPYQ_2020

PhysicsEasynumerical

A photographic camera with a lens of focal length $5 cm$ is used for capturing images. The vertical length of the film used is $24 mm$ in which image of a $1.68 m$ tall man is to be captured. Find the minimum distance (in $m$ ) of the man from the lens such that his complete image can be obtained.

Answer:

3.55

Solution:

The lens of a camera is convex and the image is inverted

$m = \frac{h_{i}}{h_{o}} = - \frac{24 m m}{1.68 m} = - \frac{1}{70}$
$m = \frac{f}{f + u} = - \frac{1}{70}$

$70 f = - f - u$

$- u = 71 f = 355 cm = 3.55 m$

Subject:PhysicsTopic:Geometrical OpticsSubtopic:Refraction at curved surface/Lens

⏱ 2mℹ️ Source: PYQ_2020

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