SSC
Sample Paper
Mock Test-20 SSC CGL Tear-II Paper-1
question_answer
A light ray emerging from the point source placed at P (2, 3) is reflected at a point Q on the y-axis and then passes through the point R (5, 10). Coordinates of Q are
A)(0, 3)
B) (0, 2)
C) (0, 5)
D) None of these
Correct Answer:
C
Solution :
If \[{{P}_{1}}\] be the reflection of P in y-axis, then \[{{P}_{1}}\equiv (-2,3).\] Equation of line\[{{P}_{1}}R\]is \[(y-3)=\frac{10-3}{5+2}(x+2)\]\[\Rightarrow \]\[y=x+5\] It meets the y-axis at \[(0,5)\]\[\Rightarrow \]\[Q\equiv (0,5)\]