A pendulum clock is running slow, In order to correct it, we should

A simple harmonic progressive wave is represented by $y = A \sin(120\pi t + 3x)$. The distance between two points on the wave at a phase difference of $\dfrac{\pi}{3}$ radian is

A pipe open at both ends has a fundamental frequency 'f' in air. The pipe is dipped in water, so that $\dfrac{2}{3}^{rd}$ length of pipe is in water, Now the fundamental frequency of the air column is

To increase the frequency of transverse oscillations of a stretched string by 40%, the tension must be increased by