ME or MEng Master of Engineering Thermodynamics and Heat Transfer 3

Question 1

Which heat transfer mode does NOT require a medium (can occur in a vacuum)?

Accepted Answer

Radiation

Answer

Conduction

Answer

Convection

Answer

Advection

Question 2

In a gas turbine (Brayton) cycle, the ideal thermal efficiency depends on:

Accepted Answer

Pressure ratio

Answer

Maximum cycle temperature only

Answer

Mass flow rate

Answer

Turbine inlet enthalpy alone

Question 3

The first law of thermodynamics applied to an open steady-flow system is expressed as:

Accepted Answer

Q − W_s = Δh + ΔKE + ΔPE

Answer

Q − W = ΔU

Answer

dS ≥ δQ/T

Answer

PV = nRT

Question 4

A fin on a heat sink increases heat dissipation primarily by:

Accepted Answer

Increasing the surface area for convection

Answer

Increasing fluid velocity near the surface

Answer

Decreasing thermal conductivity of the base

Answer

Raising the temperature of the fluid

Question 5

Exergy (availability) in thermodynamics represents:

Accepted Answer

Maximum useful work obtainable relative to the environment

Answer

Total internal energy of the system

Answer

Entropy generated during a process

Answer

Total enthalpy minus kinetic energy

Question 6

The temperature at which a gas condenses at a given pressure is called its:

Accepted Answer

Dew point

Answer

Flash point

Answer

Boiling point

Answer

Critical temperature