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Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical Optics201Hard2 minQB

PhysicsHardsingle choice

A double convex lens forms a real image of an object on a fixed screen. Now the lens is given a constant velocity $v_{0}$ along its axis and away from the screen. For the purpose of forming the image always on the screen, the object is also required to be given an appropriate velocity.

Options:

Answer:

Solution:

$\frac{1}{v} - \frac{1}{u} = \frac{1}{f}$ ; differentiating gives $\frac{d u}{d t} = \frac{u ^{2}}{v ^{2}} \frac{d v}{d t}$

With $n = \frac{s i ze o f o bj ec t}{s i ze o f ima g e}$ : $v^{'} = (1 - n^{2}) v_{0}$

Object double the image size: n = 2, giving object speed $3 v_{0}$

Answer (D)

Stream:JEESubject:PhysicsTopic:Geometrical OpticsSubtopic:201

⏱ 2mℹ️ Source: QB

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