Assertion (A): It is not possible to have interference between the waves produced by two violins of different frequency.
Reason (R): For interference of two waves, the phase difference between the waves must remain constant.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
Assertion (A) is true. For sustained interference, sources must be coherent, meaning same frequency and constant phase difference. Two violins produce incoherent waves. Reason (R) is true and correctly states the condition for interference.
Assertion (A): Energy is created during constructive interference and destroyed during destructive interference.
Reason (R): The positions of constructive interference are sources of energy while the positions of destructive interference are sinks of energy.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
Energy is always conserved in interference phenomena; it is merely redistributed, not created or destroyed. Thus, both Assertion (A) and Reason (R) are false.
Assertion (A): Wave velocity is equal to group velocity in a non-dispersive medium.
Reason (R): A non-dispersive medium is one in which the wave velocity is frequency dependent.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
In a non-dispersive medium, the phase velocity (wave velocity) \(v_p\) is constant, meaning it does not depend on frequency. In this case, group velocity \(v_g\) equals \(v_p\). So (A) is true. Reason (R) is false because a non-dispersive medium has wave velocity independent of frequency.