heat and thermodynamics

In which of following processes all three thermodynamic variables, that is pressure, volume and temperature can change?

• Isobaric

• Isothermal

• Isochoric

• Adiabatic

Numerical value of Boltzmanns constant is

• 1.38x10-31JK-1

• 3.18x10-31JK-1

• 3.18x10-23JK-1

• 1.38x10-23JK-1

The relation for the 1st law of thermodynamics can be expressed as:

An equation W=P(V₂-V₁) represent work done by a gas in

• Free expension

• An isothermal expension

• An adiabatic expension

• An expansion at constant pressure

• 8200 J

• 5600 J

• 7900 J

• 6400 J

In the given diagram the net amount of work done is

• positive

• negative

• zero

• infinity

A system is described in terms of thermodynamics variables

• Pressure

• Temperature

• Volume

• All of these

Which of the following statement is true for any thermodynamics system?

• The internal energy changes in all processes

• The change in entropy can never be zero

• Internal energy and entropy are state funsctions

• THE WROK DONE IN AN ADIABATIC PROCESS IS ALWAYS ZERO.

Answer explanation

1-No there is no change in internal energy in cyclic process and isothermal process where T= constant

2- in cyclic process change in entropy is zero.

3- yes, entropy and internal energy are state functions because they do not depends on path. Only depends on initial and final state.

4- no in adiabatic process work done is not zero. As we studied in carnot engine.

Thermodynamics is the study of relation between

• heat and surrounding

• heat and other form of energy

• heat and liquid

• heat and chemical change

Answer explanation

as heat convert into work done J

When heat is given to agas in an adiabatic process then

• The work is done by the gas

• internal energy of the gas increases

• Both A and B

• none