Waves question for NEET / JEE Main, with solution

Answer: (B) $20\%$

Concept. $v = \sqrt{\dfrac{T}{\mu}}$, so $v \propto \sqrt T$.

Step 1. New speed. $T \to 1.44T$, so $v \to \sqrt{1.44}\,v = 1.2v$.

Step 2. Increase. $20\%$.

Answer. $20\%$ (Option B).

Solution by Sreeraj P, M.Sc Physics