CBSE
Multiple Choice QuestionsThe mean free path of molecules of a gas, (radius r) is inversely proportional to,
r3
r2
r
r
The molecules of a given mass of a gas have r.m.s. velocity of 200 m/s at 27o C and 1.0 x 105 Nm-2 pressure. When the temperature and pressure of the gas are respectively, 127o C and 0.05 x 105 Nm-2, the RMS velocity of its molecules in m/s is,
The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of radius r, whose outer surface radiates as a black body at a temperature T K is given by
σr2T4/R2
σr2T4/4πR2
σr4T4/r4
An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?
mv3 /2
mv3
mv2/2
mv2/2
At 10o C the value of the density of a fixed mass of an ideal gas divided by its pressure is x. At 110o C this ratio is
x
383x/283
10x/110
10x/110
In producing chlorine by electrolysis 100 kW power at 125 V is being consumed. How much chlorine per minute is liberated (ECE of chlorine is 0.367 x 10-6 KgC-1)
1.76 x 10-3 kg
9.67 x 10-3 kg
17.61 x 10-3 kg
17.61 x 10-3 kg
An alpha nucleus of energy mv2/2 bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to
1/Ze
v2
1/m
1/v4
Two vessels separately contain two ideal gases A and B the same temperature, the pressure of A being twice that of B. Under such conditions, the density of A is found to be 1.5 times the density of B. The ratio of molecular weight of A and B is
2/3
3/4
2
2
In the given (V-T )diagram, what is the relation between pressures p1 and p2?
p2 =p1
p2>p1
p2<p1
p2<p1
A particle of mass M starting from rest undergoes uniform acceleration. If the speed acquired in time T is v, the power delivered to the particle is
Mv2/T
Mv2 / 2T2
Mv2/T2
Mv2/T2
