Physics · Science General

Units and Measurement

1,044 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 energy : forms and sources concept of energy energy for everything forms of energy

If the values of force and length are increased four times then the unit of energy will increases by?

  1. $4$ times
  2. $2$ times
  3. $8$ times
  4. $16$ times
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 Force is represented as $\left[ ML{ T }^{ -2 } \right] \quad and\quad length\left[ L \right] $

$energy\quad f\times d\quad is\left[ ML{ T }^{ -2 } \right] \quad \times \left[ L \right] =\left[ M{ L }^{ 2 }{ T }^{ -2 } \right] $
 if Force and length are quadrupled in value Energy
$4\left[ ML{ T }^{ -2 } \right] \quad \times 4\left[ L \right] =16\left[ M{ L }^{ 2 }{ T }^{ -2 } \right] $
unit increased by 16 times 

Multiple choice conductivity and its types electrochemistry

What are the units of equivalent conductivity of a solution?

  1. $mho\ cm^{-1}$
  2. $ohm\ cm^{-1} g\ equiv^{-1}$
  3. $mho\ cm^{-2}g\ equiv^{-1}$
  4. $mho\ cm^{2}g\ equiv^{-1}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
$\rightarrow$ If 1 $m^{3}$ of a solution of an electrolyte placed between two large electrodes 1m apart. The cross-sectional area of the solution will be $1m^{2}$.
$\rightarrow$ The conductance of solution will evidently be its specific conductance because we have a one-meter cube of the solution.
$\rightarrow$ If $1m^{3}$ of the solution contains 1 gram equivalent of the electrolyte.
Hence, $Conductance(C)=Specific Conductance(K)=Equivalent Conductance(\wedge)$
$\rightarrow$ As unit of Specific conductance is $Sm^{-1}$ or $Scm^{-1}$, so the unit of Equivalent Conductance is
$Scm^{-1}$ or $ mhocm^{-1}$.
$\rightarrow$ $mho$ is reciprocal of $ohm$ & reciprocal of $ohm$ i.e. $ohm^{-1}$ is also called $mho$ or $Siemen(S)$.
Multiple choice chemistry matter in our surroundings atmospheric pressure and boiling point evaporation - factors and effects in daily life changes in physical state - boiling, evaporation and condensation

Unit measure of atmospheric pressure is equal to the column of mercury pressure of _____.

  1. 76 cm

  2. 76 mm

  3. 1.013 mm

  4. 10.13 mm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The unit measure of atmospheric pressure is equal to the column of mercury pressure of 76 cm or 760 mm of mercury.

Multiple choice physics learning how to measure measurement of small and large distances measurement of distance unit of fundamental quantities

Which of the following system of units is not based on unit of mass, length and time?

  1. CGS

  2. FPS

  3. MKS

  4. SI
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The SI unit system is not based on only mass, length and time alone. 
This unit system is consists of seven fundamental units which can be given as mass, length, time, temperature, luminous intensity, mole and current.
The correct answer is option $(D)$
Multiple choice physics learning how to measure measurement of small and large distances measurement of distance unit of fundamental quantities

Which of the following is not a unit of mass?

  1. Slug

  2. Kilogram

  3. Ton

  4. Newton
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The slug is the unit of  mass in the US common system of units. 

It is a mass that accelerates by $1\ ft/s^2$ when $1$ pound force is applied. 
The kilogram (kg) is the SI unit of mass. 
Ton is also represent the unit of mass and $1$ ton is equal to $1000$ kg.
Newton is the SI unit of force. 

Multiple choice physics learning how to measure measurement of small and large distances measurement of distance unit of fundamental quantities

The unit of the quantity $g/G$ in SI will be

  1. $kg$ ${m}^{-2}$
  2. $mk$ ${g}^{-2}$
  3. ${m}^{2}$ ${kg}^{-1}$
  4. ${kg}^{2}$ ${m}^{-1}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The quantity g is acceleration due to gravity (m/s^2) and G is the universal gravitational constant (N m^2/kg^2). The ratio g/G has units (m/s^2) / (N m^2/kg^2) = (m/s^2) * (kg^2 / (kg m/s^2 * m^2)) = kg/m^2.

Multiple choice physics learning how to measure measurement of small and large distances measurement of distance unit of fundamental quantities

The average kinetic energy $E$ of a gas molecule is given by the equation$E=\cfrac{3}{2}kT$
where $T$ is the absolute (kelvin temperature)
What are the SI base units if $k$?

  1. ${kg}^{-1}{m}^{-1}{s}^{2}K$
  2. ${kg}^{-1}{m}^{-2}{s}^{2}K$
  3. $kg$ ${ms}^{-2}{K}^{-1}$
  4. $kg{m}^{2}{s}^{-2}{K}^{-1}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Here ,

$E = \dfrac{3}{2}kT$
$\implies k= \dfrac{2E}{3T}$
$\implies [k] = \dfrac{[E]}{[T]}$
$\implies [k] = \dfrac{kgm^{2}s^{-2}}{K}$
$\implies [k] = kgm^2s^{-2}K^{-1}$

Multiple choice physics learning how to measure measurement of small and large distances measurement of distance unit of fundamental quantities

What is the advantage of choosing the wavelength of light as a standard of length?

  1. Travels fast

  2. Speed independent of location and temperature

  3. No medium to travel

  4. No advantage
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Advantage :

1) It is easy available and invariable

2) It is well defined and does not change with locations, temperature, time, pressure etc