Physics 2 Marks Questions

When temperature is low and pressure is high, the intermolecular forces become appreciable. Moreover, the volume occupied by the molecules would not be negligibly small as compared to the volume of the gas. Thus, the behavior of real gases at high pressure and low temperature deviates largely from the behavior of ideal gases.

As PV directly proportional to constant in isothermal process. Thus volume varies slowly w.r.t pressure. As in adiabatic process the volume decreases as PV directly proportional to constant. So, isothermal process is slow process and adiabatic process is fast process.

Temp is 20° Relative humidity = 100% So the air is saturated at 20°C Dew point is the temperature at which SVP is equal to present vapour pressure, So 20°C is the dew point.

Temp = 20°C Dew point = 10°C The place is saturated at 10°C Even if the temp drop dew point remains unaffected. The air has V.P. which is the saturation VP at 10°C. It (SVP) does not change on temp.

At low temperature, diatomic gas has three translational and two rotational degrees of freedom, so total number of degrees of freedom is 5. But at high temperature, gas molecule starts to vibrate which give two additional degrees of freedom i.e. 7.

No, In a system either temperature varies or it heat varies. In case of ideal gas Internal energy is function of temperature only thus for isothermal process change in internal energy is zero. Now, since process is adiabatic thus heat exchange is zero. therefore, work done is also zero.

For monoatomic gas, temperature rise will be greater because monoatomic gas possesses only translational degree of freedom whereas diatomic gas translation, rotation and vibrational (at higher temperature), so temperature rise for diatomic gases is lower.

When the piston is pulled out, the volume of the gas increases. Now, lesser number of molecules collide against the wall per unit time. Moreover, the collisions take place over a large area. Due to both these reasons, the pressure decreases.

Yes, we can connect two process one after another as it is explained in cannot cycle. First we let gas expand as isothermal process then insulate it and make it adiabatic process.

This is because scent vapour molecules do not travel uninterrupted, they undergo a number of collisions and trace a zig-zag path, due to which their effective displacement per unit time is small, so spreading is at a much slower rate.

Because the gas inside cylinder is in liquid form it converts in to gas and occupies rest of the cylinder when the liquid gas is finished there is no more liquid to convert into gas thus in last few minutes the pressure inside cylinder reduces noticeably.

As in isothermal PV is directly proportional to 1. In adiabatic process, PV is directly proportional to 1. As in adiabatic process pressure varies the volume varies as its powers w.r.t pressure so it decreases with more slope.

As in pressure cooker liquid is changed in to vapors and they increase pressure inside cooker as we know pressure is directly proportional to temperature thus temperature increases along with pressure thus food is cooked faster.

According to kinetic theory, molecules of a liquid are in a state of continuous random motion. The molecules near the surface of liquid may have enough K.E. so as to overcome the intermolecular attraction of other molecules on the surface and hence manage to escape. Such molecules would move around freely in the space above the liquid. This is the phenomenon of evaporation which may occur at all temperatures.