Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsReflection at curved surfaceEasy2 minPYQ_2015

PhysicsEasysingle choice

A ray parallel to principal axis is incident at $3 0^{\circ}$ from normal on concave mirror having radius of curvature $R$ . The point on principal axis where rays are focussed is $Q$ such that $PQ$ is

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Solution:

From similar triangles,
$\frac{QC}{sin 3 0 ^{\circ}} = \frac{R}{sin 12 0 ^{\circ}}$ or $QC = R \times \frac{s i n 3 0 ^{\circ}}{s i n 12 0 ^{\circ}} = \frac{R}{3}$ Thus $PQ = PC - QC = R - \frac{R}{3} = R (1 - \frac{1}{3})$

Stream:BITSATSubject:PhysicsTopic:Geometrical OpticsSubtopic:Reflection at curved surface

⏱ 2mℹ️ Source: PYQ_2015

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