Physics 1 Marks Question

Yes, by doing work to change its volume (decrease).

It is a device that helps in maintaining a constant temperature. It consists of a bi-metallic strip which comprises of two thin strips of different materials (such as brass and invar) welded together along their lengths. On heating, this combination bends into an arc. It happens because brass has a higher coefficient of expansion than invar.

The efficiency is independent of the nature of the working substance.

Yes.

This happens due to adiabatic expansion of the air of the tube of the bicycle.

No.

If two isothermal curves intersect, this implies that the pressure and volume of a gas are the same at two different temperatures, that's impossible.

Leaking of air is adiabatic expansion and adiabatic expansion produces cooling.

According to second law, it is not possible to cool a system cooler than its surroundings without doing work on it.

An indicator diagram is a graphical representation of the state of a system with the help of two thermodynamic variables (generally pressure and volume). Work done by a system is numerically equal to area under the P-V indicator diagram.

It leads us to the concept of temperature.

Yes, change in internal energy depends on the change in temperature alone. So, it is independent of path.

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

The P-V diagram for an isobaric process is a straight line parallel to volume axis while that for an isochoric process, it is a straight line parallel to pressure axis.

Internal energy of the system will increase by 40 + 10 = 50 joule.

The perforations in it will get filled with water and the air is released as bubble.

No engine working between two temperatures can be more efficient than a Carnot's reversible engine working between the same temperatures.

Zero, because for an ideal gas internal energy is wholly kinetic and it is a function of temperature. As temperature remains constant in an isothermal process, hence, internal energy of an ideal gas remains constant.

Flat portion refers to the transition from gas to liquid as the gas is compressed. As temperature increases, the flat portion's size reduces.

Change in pressure will be more than 3 times the initial pressure.

It can go down only upto 4°C.

Yes, for example in an adiabatic expansion and explosion of a bomb (chemical energy is converted into K.E.).

Zero.

In opening of bottle, adiabatic expansion of gas causes lowering of temperature.

No, we cannot design an ideal Carnot engine in practice.

This is because in the cloudy night, heat radiated out from earth is reflected by the clouds back to earth. Hence, temperature of the earth does not fall.

A gas has greatest internal energy and a solid has the least internal energy.

According to second law of thermodynamics, heat energy cannot converted into work completely.

Because work done in compressing the gas increases the internal energy of the gas.

Yes, by reducing pressure on water, boiling point of water can be brought down to room temperature.

The mechanical work can be completely converted into heat, but heat extracted from somebody cannot be completely converted into useful work.

No, beyond critical temperature, it is not possible to liquefy however large the pressure may be.

Carnot cycle is a reversible cyclic process through which heat is converted into mechanical work.

No, the coefficient of performance of refrigerator decreases with decrease in its inside temperature.