A particle is performing S.H.M. about its mean position with an amplitude ' $a$ ' and periodic time ' $T$ '. The speed of the particle when its displacement from mean position is $\frac{a}{3}$ will be

In case of photoelectric effect, the graph of measured stopping potential $\left(\mathrm{V}_0\right)$ against frequency ' $v$ ' of incident light is a straight line. The slope of this line multiplied by the charge of electron (e) gives

Critical angle of light passing from glass to air is minimum for wavelength of

What is the pressure of hydrogen in a cylinder of volume 10 litre if its total energy of translation is $7.5 \times 10^3 \mathrm{~J}$ ?