A string of length 0.4 m and mass 10−2 kg is tightly clampled at its ends. The tension in the string is 1.6 N. identical wave pulses are produced at one end at equal intervals of time ∆t. The minimum value of ∆t, which allows constructive interference between succesive pulses, is :
Mass per unit length of the string,
∴ Velocity of wave in the string.
For constructive interference between successive pulses:
(After two reflections, the wave pulse is in same phase as it was produced, since in one reflection its phase changes by π and if at this moment next identical pulse is produced, then constructive interference will be obtained.)