Q 01/05

How many laws of thermodynamics are there?

A) Four

B) Three

C) Two

D) Five

Answer · why

A) Four

The zeroth law was added after the other three were already numbered, because renumbering them was impractical.

Q 02/05

Which way does heat never flow on its own, according to a classic statement of the laws?

A) From a hotter body to a colder one

B) From a colder body to a hotter one

C) Between two bodies of equal size

D) Through a vacuum between bodies

Answer · why

B) From a colder body to a hotter one

That everyday observation is one traditional way of stating the second law.

Q 03/05

Which law of thermodynamics expresses the conservation of energy?

A) Zeroth law

B) Second law

C) First law

D) Third law

Answer · why

C) First law

Energy can be transformed from one form to another but cannot be created or destroyed.

Q 04/05

What is absolute zero on the Celsius scale?

A) −373.15 °C

B) −459.67 °C

C) −300 °C

D) −273.15 °C

Answer · why

D) −273.15 °C

The same point is −459.67 °F and 0 on both the Kelvin and Rankine scales.

Q 05/05

Which temperature scale is defined with absolute zero as 0?

A) Kelvin

B) Fahrenheit

C) Celsius

D) Réaumur

Answer · why

A) Kelvin

The Rankine scale also starts at absolute zero but uses Fahrenheit-sized degrees.