Physics 1 Marks Question

Depending on the process carried out, the work done varies. So, it is dependent on path.

Kelvin and Celsius scales never coincide.

No, as internal energy might change due to both heating and performance of work.

A reversible process is never possible in nature because of dissipative forces and condition for a quasi-static process is not practically possible.

When a gas expands, it does work on the surroundings. This work is done on the expense of internal energy and that is why its internal energy and so its temperature decreases.

No, since then for two different sets of physical parameters the system may be identified, leading to different states.

Yes, for example in adiabatic compression.

Due to transmission loss, the energy required to carry the process itself and the inability to build a sink at zero kelvin, one cannot get 100% efficient Carnot's engine.

Variation of specific heat of water with temperature:

The efficiency of a Carnot engine can be 100% if the temperature of sink is absolute zero.

The statement may not be true always because heat content of a body depends on mass of body, its specific heat and temperature.

No, Camphor.

To make the vehicle to move at constant speed, constantly the brake has to be applied to work against the available energy. So, it gets heated up.

No, a ship cannot be moved in a sea by the use of the energy of sea water because refrigerator is against the second law of thermodynamics.

Yes, in an adiabatic process the temperature of an isolated system changes. It increases when the gas is compressed adiabatically.

The coefficient of performance of a refrigerator depends on the temperatures of source and sink.

According to first law of thermodynamics when some quantity of heat (dQ) is supplied to a system capable of doing external work, then quantity of heat absorbed by the system (dQ) is equal to sum of increase in internal energy of system (dU) due to rise in temperature and external work done by system (dW) in expansion i.e. dQ = dU + dW

Second law of thermodynamics, which says that 100% conversion of heat into work is impossible.

It is based on the fact that the change in volume of mercury is nearly proportional to the change in temperature.

Heat lost by a body is equal to heat gained by the other when they are mixed.

Yes, internal energy of lead increases. No heat energy from outside enters the lead.

-40°C.

The efficiency of a carnot engine depends on the temperature of source of heat and the sink.

1. Zeroth law defines temperature.
2. First law defines internal energy.