Units, Units, Units! Trivia Quiz

Answer: SI

The SI, the International System of Units, or Le Système international d'unités, is widely acknowledged as the standard system of units of measurement. Most of its units are derived from the MKS (Metre-Kilogram-Second) system. Most countries today use SI units, though some prefer to use CGS (Centimetre-Gram-Second) or FPS (Foot-Pound-Second) systems.

Answer: kg.m/s^2

As force is the product of mass and acceleration, one newton(N) equals the product of the units of mass and acceleration i.e. kg.m/s^2. It was named after the noted physicist and mathematician, Sir Isaac Newton. kg.m^2/s^2 is equal to one joule, the unit of work done and kg.m^2/s^3 equals one watt, the unit of power. The unit kg^2.m.s doesn't exist.

Answer: One second

A second, the unit of time is also defined as 1/86 400 of a mean solar day and is common to all systems of measurement. In 1956, the International Congress of Weights and Measures precisely redefined the second as 1/31 556 925.9747 of the tropical year 1990. However, in 1967, it was standardised as being equal to the time taken for a Cs-133 atom to complete 9 192 631 770 vibrations.

Answer: Siemens

The unit of resistance is ohm, and its reciprocal is siemens or mho, the unit of conductance. Both mho and siemens are used commonly. Farad, henry and weber are the units of capacitance, inductance and magnetic pole strength respectively.

Answer: False

The radian is the unit of linear angle, and is an independent or fundamental unit. Though it is a standard SI unit, degrees, minutes and seconds are commonly used in place of radian, as the calibration of an angle is easier in the degree measure.

Answer: Nano

Nano stands for 10^-9 or 1/1,000,000,000, which is the smallest among the options. Micro stands for 1/1,000,000, deca stands for 10 and milli stands for 1/1,000.

Answer: Joule

James Prescott Joule, a 19th century physicist, was responsible for determining the mechanical equivalent of heat. His name is also remembered in two laws. Due to his contributions to thermodynamics, the SI unit of work or energy was named after him. Note that all the other options, tesla, henry, newton are SI units named for scientists.

Answer: A.m^2

Magnetic moment(M) is the product of pole strength(m) and total length of a bar(2L) magnet. The SI units of these are A.m and m, the product of which is A.m^2.

Answer: True

Ratios generally have no units, but this particular ratio does have a unit - the mole(mol). It is also known as the amount of substance.

Answer: Magnitude x unit

Originally, people had no idea of units and their relevance to a quantity and the necessity to attach it with magnitude. With growing trade, scientific knowledge and precision in many things, man's knowledge increased. On the whole, it is the amount of the physical quantity in nature with respect to the specified unit.