Two tuning forks when sounded together produce 4 beats per second. One of the forks is in unison with 23 cm length of sonometer wire and other with 24 cm length of the same wire. The frequencies of the two tuning forks are

Let the speed of light and the polarising angle for a given medium be ' $V$ ' and ' $i_p$ ' respectively. The relation between them is : ( $\mathrm{C}=$ speed of light in vacuum)

The equivalent resistance of the following circuit when no current flows in the resistance of $5 \Omega$ is nearly

In the case of common emitter transistor amplifier, the ratio of collector current to emitter current is 0.96 , then the current gain $(\beta)$ of the amplifier is