At a certain place, the angle of dip is 30º and the horizontal component of earth’s magnetic field is 0.50 oerested. The earth’s total magnetic field (in oerested) is

In Vander Waal’s equation the critical pressure P_c is given by

At identical temperatures, the rms speed of hydrogen molecules is 4 times that for oxygen molecules. In a mixture of these in mass ratio H₂: O₂= 1:8, the rms speed of all molecules is n times the rms speed for O₂ molecules, where n is

The order of magnitude of the number of nitrogen molecules in an air bubble of diameter 2mm under ordinary conditions is

Graph of specific heat at constant volume for a monatomic gas is

At what temperature, pressure remaining constant, will the r.m.s. velocity of a gas be half of its value at 0º C

N molecules, each of mass m,of gas A and 2 N molecules,each of mass 2 m, of gas B are contained in the same vessel which is maintained at a temperature T. The mean square of the velocity of molecules of B type is denoted by v² and the mean square of the X component of the velocity of A type is dentoed by ω², ω²/v² is

If pressure of a gas contained in a closed vessel is in creased by 0.4% when heated by 1ºC, the initial temperature must be

The value of critical temperature in terms of van der Waal’s constant a and b is given by

The air in a room has 15 gm of water vapours per cubicmetre of its volume. However for saturation one cubic metre of volume requires 20 gm of water vapour then relative humidity is