Two identical piano wires have same fundamental frequency when kept under the same tension. What will happen if tension of one of the wires is slightly increased and both the wires are made to vibrate simul- taneously ?

When two identical piano wires are kept under the same tension, they share the same fundamental frequency. The fundamental frequency of a stretched string is proportional to the square root of its tension. If the tension of one wire is slightly increased, its frequency also increases slightly, creating a small frequency difference between the two wires. When these two sound waves with slightly different frequencies are played simultaneously, they undergo constructive and destructive interference. This interaction results in periodic variations in sound intensity known as beats. The beat frequency is equal to the absolute difference between the frequencies of the two vibrating wires. This phenomenon is commonly used by musicians and tuners to adjust instrument pitch by listening for the pulsating effect of the beats.