Thermodynamics

Question 1

What is a Thermodynamic system?

Answer 1

This is a system that interacts and exchanges energy with its environment.

Question 2

What is a closed system?

Answer 2

A closed system is a system in which the transfer of matter from it to the environment is not permitted, but the transfer of energy is.

Question 3

What is an open system?

Answer 3

An open system exists such that matter and energy is exchanged between it and its environment.

Question 4

What is the first law of thermodynamics?

Answer 4

The amount of heat energy supplied to a system equals the sum of the change of internal energy and the work done by/on that system.

Question 5

What happens in adiabatic process?

Answer 5

Quantity of heat (∆Q) is zero.

Question 6

What is the formula for adiabatic process when pressure is not given?

Answer 6

T₁V₁^{γ - 1} = T₂V₂^{γ - 1}

Question 7

What is the formula for work done in an isothermal process?

Answer 7

∆W = P₁V₁ × ln(V₂ ÷ V₁)

Question 8

What is the relationship of work done between two gases in an adiabatic system?

Answer 8

P₁V₁^γ = P₂V₂^γ

γ = Cp/Cv

Cp = specific heat capacity at constant pressure

Cv = specific heat capacity at constant volume

Question 9

What is the second law of thermodynamics?

Answer 9

Heat is spontaneously transferred from a hotter to a cooler body, and never in the opposite direction.

Question 10

What is the ratio of heat to temperature in a Carnot engine?

Answer 10

Q_c/Q_h = T_c/T_h

Question 11

What is the expression for efficiency in a Carnot engine?

Answer 11

(1 - T_c/T_h) × 100

Or

(1 - Q_c/Q_h) × 100

Question 12

What is the expression for coefficient of performance?

Answer 12

T_c/(T_h - T_c)