A gas undergoes a change in which its pressure ' P ' and volume ' V ' are related as $\mathrm{PV}^{\mathrm{n}}=$ constant, where n is a constant. If the specific heat of the gas in this change is zero, then the value of $n$ is ( $\gamma=$ adiabatic ratio)

From photoelectric effect experiment, select the correct statement.

The equation of wave is $y=60 \sin (1200 t-6 x)$, where ' $y$ ' is in micron, ' $t$ ' is in second and ' $x$ ' is in metre. The ratio of maximum particle velocity to the wave velocity of wave propagation is

Two satellites P and Q go round a planet in circular orbits having radii ' $3 R$ ' and ' $R$ ' respectively. If the speed of satellite $P$ is ' $2 V$ ', the speed of the satellite $Q$ will be