question_answer 32)

                  Four pendulums A, B, C and D are suspended from the same                 elastic support as shown in fig. A and C are of the same length, while B is smaller than A and D is larger than A. If A is given a transverse displacement. (a) D will vibrate with maximum amplitude. (b) C will vibrate with maximum amplitude. (c) B will vibrate with maximum amplitude. (d) All the four will oscillate with equal amplitude.

Answer:

                  (b) Since lengths of both pendulums A and C are equal, so they have same time period. When pendulum A vibrates, then pendulum C will vibrate with maximum amplitude because the frequencies of both these pendulums match the hence resonance takes place.