Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsReflection at curved surfaceEasy2 minPYQ_2020

PhysicsEasynumerical

At what distance (in $m$ ) from a convex mirror of focal length $2.5 m$ should a boy stand so that his image has a height equal to half of his height? The principal axis of the mirror is perpendicular to the height of the boy.

Answer:

2.50

Solution:

We have,
$m = - \frac{v}{u} = \frac{1}{2}$
$v = - \frac{u}{2}$
$\frac{1}{u} + \frac{1}{v} = \frac{1}{f}$
$\frac{1}{u} + \frac{1}{- u / 2} = \frac{1}{2.5 m}$
$- \frac{1}{u} = \frac{1}{2.5 m}$
$u = - 2.5 m$

Thus, he should stand at a distance of $2.5 m$ from the mirror.

Subject:PhysicsTopic:Geometrical OpticsSubtopic:Reflection at curved surface

⏱ 2mℹ️ Source: PYQ_2020

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