Thermodynamics Quest EC

According to kinetic theory of gases, the absolute zero temperature is attained when

• When mass is zero

• Kinetic Energy of gas molecules is zero

• Pressure of gas molecules is zero

• Volume of gas is zero

1200 J of heat are added to a sample of gas while 400 J of work is done by the gas. What is the change in internal energy of the gas?

• 800 J

• 1600 J

• -800 J

• -1600 J

What does the "U" stand for the formula ∆U = Q + W

• Heat
• Temperature
• Work
• Internal energy

40J of work is done by a gas when the system has an increase in internal energy of 125J. What energy is needed to do so?

• 165J

• 85J

• Can´t be possible

• 165Cal

An ideal gas undergoes the thermodynamic changes represented in the P –V diagram below

(P → Q → R → P).

Which of the following is the net work done by the gas in a cycle?

• 4.5 × 10⁵ J

• 3.0 × 10⁵ J

• 1.0 × 10⁵ J

• Zero

The diagram shows the pressure-volume relationship for a fixed mass of an ideal gas that undergoes a cycle XYZ.

In which part(s) of the cycle is external work done on the gas?

• Y → Z only

• Y → Z and Z → X only

• X → Y and Z → X only

• X → Y only

The diagram shows the pressure–volume (PV) relationship for a gas.

Which of the following area(s) is/are equal to the work done by the gas as it expands?

• area I

• area II

• area I + area II

• area I – area II

Process B on the PV diagram is an ______________ process.

• adiabatic

• isobaric

• isochoric

• isothermal

A thermodynamic system where no exchange of heat takes place between system and surrounding is...

• Isothermal process

• Adiabatic process

• Isobaric process

• Isochoric process

When applying the first law of thermodynamics to a system, when is heat a positive quantity?

• when the system does work
• when the system has work done on it
• when the system absorbs heat
• when the system loses heat
• when no work is done either on the system or by the system