A stretched uniform sonometer wire between two fixed knife edges vibrates in its second harmonic and gives 1 beat per second with a 200 Hz tuning fork. Find the percentage change in wire tension required for unison with the fork.
Physics · Wave Motion
JEE Mains Practice

Question

A stretched uniform sonometer wire between two fixed knife edges vibrates in its second harmonic and gives 1 beat per second with a 200 Hz tuning fork. Find the percentage change in wire tension required for unison with the fork.

Physics · Wave Motion

G1 Physics · Accepted Answer

Step 1: For a stretched string, v = √(T/μ) and fₙ = nv/(2L) for fixed ends. Step 2: Use the stated node/antinode or harmonic condition; for composite wires the same frequency must hold on both parts. Step 3: Solve with the given lengths, densities and tension. Final: 1.