Physics · Science General

Units and Measurement

998 Questions

Master the fundamentals of physics with these practice questions on units and measurement. The topics include fundamental SI units, derived quantities, and specific units for power, force, and light. These questions are essential for building a strong foundation for competitive exams.

SI fundamental unitsUnits of powerDerived quantities unitsThermal energy unitsVolume measurement unitsElectric current units

Units and Measurement Questions

Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

The SI unit of magnetic permeability is:

  1. ${ Am }^{ -1 }$
  2. ${ Am }^{ -2 }$
  3. ${ Hm }^{ -2 }$
  4. ${ Hm }^{ -1 }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Magnetic permeability is a constant of proportionality that exists between magnetic induction and magnetic field intensity. 

In SI units, permeability is measured in henries per meter $H/m$ or $H m^{-1}$.
Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

Any unit which can be obtained by the combination of one or more fundamental units is called

  1. Fundamental unit

  2. Scale

  3. Derived unit

  4. Standard unit
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The units which can neither derived from one another nor resolved into any thing more basic are called fundamental unit. It is independent of any other unit. Any unit which can be obtained by the combination of one or more fundamental units is called derived unit.

Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

Derived units can be defined in terms of one or multiple fundamental units.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The units of fundamental quantities (length, mass,time) are known as fundamental units(meter, kilogram, second).
The derived quantities are the quantities defined in terms of fundamental quantities via a quantitative equation. Hence, the units of these fundamental quantities involved in the equation defines the derived units.
Hence, the given statement is true.
Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

Which of the following physical quantities has neither dimensions nor unit?

  1. angle

  2. Luminous intensity

  3. Coefficient of friction

  4. Current
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Unit of angle is radian, that of luminous intensity is candela and that of current is Ampere. Coefficient of friction is unitless and dimensionless.

Coefficient of friction$=\dfrac{Applied force}{Normal reaction}$
$=\dfrac{[MLT^{-2}]}{[MLT^{-2}]}=$No dimensions
Unit $=\dfrac{N}{N}=$No unit.

Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

The unit of Stefans constant $\sigma$ is:

  1. $\dfrac{{watt}^{4}}{m{K}^{4}}$
  2. $\dfrac{calorie}{{m}^{2}{K}^{4}}$
  3. $\dfrac{watt}{{m}^{2}{K}^{4}}$
  4. $\dfrac{joule}{{m}^{2}{K}^{4}}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Stefan's law states P = sigma * A * T^4. Rearranging for sigma gives P/(A * T^4), which has units of Watt/(m^2 * K^4).