Assertion Velocity of particles while crossing mean position varies from maximum at antinodes to zero at…
Assertion Velocity of particles while crossing mean position varies from maximum at antinodes to zero at nodes.
Reason Amplitude of vibration at antinodes is maximum and at nodes, the amplitude is zero and all particles between two successive nodes cross the mean position together.
(a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.
Solution
A stationary (standing) wave can be written as a superposition of two travelling waves of equal amplitude moving in opposite directions. It has fixed nodes (points of zero amplitude) and antinodes (points of maximum amplitude).
Thus the description (node = zero amplitude, antinode = maximum amplitude) is correct and follows from the stationary wave representation.