Q 01/05

The kelvin is the base unit of temperature in which set of units?

A) The centimetre-gram-second (CGS) system

B) The International System (SI)

C) United States customary units

D) The British Imperial system

Answer · why

B) The International System (SI)

The International System (SI). The kelvin is one of its seven base units, yet outside the laboratory most people meet it on light-bulb packaging, as a...

Q 02/05

The cosmic microwave background, the afterglow of the Big Bang, has cooled to roughly what temperature?

A) 0.03 K

B) 2.7 K

C) 270 K

D) 27,000 K

Answer · why

B) 2.7 K

2.7 K. The light set out at about 3,000 K when the first atoms formed, and the stretching of space ever since has cooled it to within three kelvins of...

Q 03/05

What do you add to a Celsius temperature to convert it to kelvins?

A) 32.00

B) 100.00

C) 273.15

D) 546.30

Answer · why

C) 273.15

273.15. A kelvin is exactly the same size as one step on the Celsius scale, so the two differ only by this fixed offset, which is why water freezes at...

Q 04/05

What temperature does 0 K represent?

A) The triple point of water

B) The boiling point of helium

C) Absolute zero

D) The freezing point of water

Answer · why

C) Absolute zero

It is the lowest possible temperature, the point at which classical particle motion would stop.

Q 05/05

Kelvin's first published papers, written at 16 and 17, defended which French scientist's theory of heat flow?

A) Pierre-Simon Laplace

B) Siméon Denis Poisson

C) Augustin-Louis Cauchy

D) Joseph Fourier

Answer · why

D) Joseph Fourier

Joseph Fourier. By his own account he mastered Fourier's book on heat in a fortnight at 15, and when British critics attacked it he rushed into print ...