Published by:
CGP EDU Academic Team
Published on: August 14, 2026
A plane mirror is placed at the origin so that the direction ratios of its normal are 1, –1, 1. A ray of light, coming along the positive direction of the x-axis, strikes the mirror. The direction cosines of the reflected ray are
A
B
– 
C
D
Text Solution
Verified by ExpertsThe correct answer is:
D
If θ θ is the angle between the normal to the plane and the incident ray, then
cos θ θ = 
. If l, m, n are the d.c of the reflected ray, then
, 
and 
⇒ ⇒ l = – 
, m = – 
, n = 
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
The projection of any line on co-ordinate axes be respectively then square of its length is
If , then projection of on the plane is . Find .
If the x -co-ordinate of a point P on the join of Q (2, 2, 1) and R (5, 1, –2) is 4, then its z -co…
If centroid of tetrahedron OABC , where A , B , C are given by ( a , 2, 3), (1, b , 2) and (2, 1, c…
A line passes through the points (6, –7, –1) and (2, –3, 1). The direction cosines of line, so dire…
If A , B , C , D are the points (3, 4, 5) (4, 6, 3), (–1, 2, 4) and
(1, 0, 5), then the projection …