Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsRefraction at curved surface/LensMedium2 minPYQ_2024

PhysicsMediumnumerical

The distance between object and its two times magnified real image as produced by a convex lens is $45 cm$ . The focal length of the lens used is ________ $cm$ .

Answer:

10.00

Solution:

Magnification, $m = \frac{v}{u} = - 2$

$\Rightarrow v = - 2 u \dots (i)$

As,

$v - u = 45 \dots (ii)$

$\Rightarrow u = - 15 cm$

Then, $v = 30 cm$

From lens equation, we can write

$\frac{1}{f} = \frac{1}{v} - \frac{1}{u} \Rightarrow \frac{1}{f} = \frac{1}{30} - \frac{1}{(- 15)}$

$\Rightarrow f = + 10 cm$

Stream:JEESubject:PhysicsTopic:Geometrical OpticsSubtopic:Refraction at curved surface/Lens

⏱ 2mℹ️ Source: PYQ_2024

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