A pergect gas of volume 5 litre is compressed isothermally to volume of 1 litre. The r.m.s. speed of the molecules will

An electron of mass ' $m$ ' and charge ' $q$ ' is accelerated from rest in a uniform electric field of intensity ' $E$ '. The velocity acquired by it as it travels a distance ' $l$ ' is ' $v$ '. The ratio $\frac{\mathrm{q}}{\mathrm{m}}$ in terms of $E, l$ and $v$ is

In a biprism experiment, monochromatic light of wavelength ' $\gamma$ ' is used. The distance between the two coherent sources ' $d$ ' is kept constant. If the distance between slit and eyepiece ' $D$ ' is varied as $D_1, D_2, D_3, D_4$ and corresponding measured fringe widths are $\mathrm{W}_1, \mathrm{~W}_2, \mathrm{~W}_3, \mathrm{~W}_4$ then

The ratio of weight of a man in a stationery lift and weight when the lift is moving downward with a uniform acceleration ' $a$ ' is $3: 2$. Then the value of ' $a$ ' is