Q 01/05

How many base units does the modern International System of Units (SI) have?

A) Seven

B) Four

C) Five

D) Nine

Answer · why

A) Seven

They are the metre, kilogram, second, ampere, kelvin, mole and candela; everything else, from the newton to the tesla, is derived from them.

Q 02/05

The metric prefix "kilo" multiplies a unit by what factor?

A) 100

B) 500

C) 1,000

D) 2,000

Answer · why

C) 1,000

"Milli" divides by the same factor, so a milligram is a thousandth of a gram.

Q 03/05

What is the process of adopting the metric system called?

A) Decimalisation

B) Standardisation

C) Metrication

D) Rationalisation

Answer · why

C) Metrication

The SI has been adopted as the official system of weights and measures in almost every country in the world.

Q 04/05

Besides America, which two countries did NIST identify as lacking mandatory metric laws?

A) Jamaica and Belize

B) Liberia and Myanmar

C) Samoa and Tonga

D) Yemen and Bhutan

Answer · why

B) Liberia and Myanmar

Both have since announced moves toward the metric system, with Liberia pledging to adopt it in 2018.

Q 05/05

The metric system was formally defined in French law on 7 April of which year?

A) 1795

B) 1799

C) 1804

D) 1815

Answer · why

A) 1795

The same decree fixed the gram as the weight of a cubic centimetre of water at the temperature of melting ice.