Student Login

Home›Chapters›Ray Optics PYQs›Reflection & Mirrors›Question 46

NEET 2017 · Reflection & Mirrors

Reflection & Mirrors question from NEET 2017

Q46NEET 2017Medium

Reflection & Mirrors

A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L. When the mirror is rotated through a small angle $\theta$ , the spot of the light is found to move through a distance y on the scale. The angle $\theta$ is given by

Show answer and solution

Answer: (d)

When a mirror rotates by $\theta$ , the reflected ray rotates by $2\theta$ .
For a small angle, spot shift $y = x \cdot 2\theta$
$\theta = \frac{y}{2x}$ , so the answer is (d).

Report a mistake

More questions on Reflection & Mirrors

Match the corresponding entries of column 1 with column 2. [Where m is the magnification…NEET 2016 (Phase 1)
You are asked to design a shaving mirror assuming that a person keeps it 10 cm from his…JEE Main 2015 (10 Apr, Shift 1)
Two plane mirrors are inclined at 70°. A ray incident on one mirror at angle, θ after…NEET 2013
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length…NEET 2012 (AIPMT, Mains)
A car is fitted with a convex side-view mirror of focal length 20 cm. A second car 2.8 m…JEE Main 2011 (AIEEE)
To get three images of a single object, one should have two plane mirrors at an angle ofJEE Main 2003 (AIEEE)
If two mirrors are kept at 60° to each other, then the number of images formed by them isJEE Main 2002 (AIEEE)
A tall man of height 6 feet, want to see his full image. Then required minimum length of…NEET 2000 (AIPMT)