BITSAT2015PhysicsRay OpticsActual
A ray parallel to principal axis is incident at 30^ 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
Options
- AR 2
- BR 3
- C2 R -R 2
- DR (1- 1 3 )
Correct answer
D. R (1- 1 3 )
Step-by-step solution
From similar triangles, Q C 30^ = R 120^ or Q C=R 30^ 120^ = R 3 Thus P Q=P C-Q C=R- R 3 =R (1- 1 3 )