Ramsay Test Thermodynamics 4

Question 1

What does a Carnot cycle represent in thermodynamics?

Accepted Answer

The most efficient possible heat engine

Answer

A real combustion engine

Answer

A perpetual motion machine

Answer

An isolated cooling system

Question 2

As the temperature of a gas increases at constant volume, what happens to its pressure?

Accepted Answer

It increases

Answer

It decreases

Answer

It stays the same

Answer

It drops to zero

Question 3

What is the term for heat that changes a substance's temperature without changing its phase?

Accepted Answer

Sensible heat

Answer

Latent heat

Answer

Heat of fusion

Answer

Heat of vaporization

Question 4

A heat engine's thermal efficiency is the ratio of work output to what?

Accepted Answer

Heat input

Answer

Heat rejected

Answer

Work input

Answer

Entropy change

Question 5

What process describes a substance changing directly from solid to gas?

Accepted Answer

Sublimation

Answer

Evaporation

Answer

Condensation

Answer

Fusion

Question 6

On the Kelvin scale, what value corresponds to absolute zero?

Accepted Answer

0 K

Answer

273 K

Answer

-273 K

Answer

100 K

Question 7

Why is a vacuum used between the walls of a thermos flask?

Accepted Answer

To reduce conduction and convection

Answer

To increase radiation

Answer

To store heat energy

Answer

To raise internal pressure