Arrange the following steps in a sequential order to verify the laws of reflection.
(A) A hard , smooth surface (AB) is mounted vertically over a horizontal board on which two tubes P and Q , point towards the surface AB.
(B) The tube Q is adjusted such that the listener would be able to hear the ticking sound clearly at the end away from AB.
(C) The sound waves from a source , like ticking clock are directed to the surface AB through the pipe P inclined at an angle to AB .
(D) By measuring the angles the tubes make with the surface AB , the laws of reflection are verified .

Options

A. ABCD
B. ACBD
C. DCBA
D. CDAB

Answer

B

Explanation

A hard , smooth surface (AB) is mounted vertically over a horizontal board on which two tubes P and Q , point towards the surface AB (a) . The sound waves from a source , like ticking clock are directed to the surface AB through the pipe P inclined at an angle to AB (c) . The tube Q is adjusted such that the listener would be able to hear the ticking sound clearly at the end away from AB (b) . By measuring the angles the tubes P and Q make with the surface AB , the laws of reflection are verified (d) .