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 chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

Unit of frequency factor (A) is:

  1. mol/L

  2. mol/L.s

  3. depend upon order of reaction

  4. it does not have any unit
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Arrhenius equation is k = A * e^(-Ea/RT). The units of the frequency factor A must match the units of the rate constant k, which depend on the order of the reaction (e.g., s^-1 for first order, M^-1 s^-1 for second order).

Multiple choice physics free, damped and forced oscillations forced vibration forced vibrations free, forced and damped oscillations

A student performs an experiment for determination of $\Bigg \lgroup g = \frac{4\pi^2 l}{T^2} \Bigg \rgroup$, l = 1m, and he commits an error of $\Delta l$ For T he takes the time of n oscillations with the stop watch of least count $\Delta T$ and he commits a human error of 0.1 s. For which of the following data, the measurement of g will be most accurate?

  1. $\Delta L = 0.5, \ \Delta T = 0.1 , \ n = 20$
  2. $\Delta L = 0.5, \ \Delta T = 0.1 , \ n = 50$
  3. $\Delta L = 0.5, \ \Delta T = 0.01 , \ n = 20$
  4. $\Delta L = 0.5, \ \Delta T = 0.05 , \ n = 50$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is given that $g$ is determined by $:g = \frac{{4{\pi ^2}l}}{{{T^2}}}$

Taking log and differentiating$,$
$ \Rightarrow \frac{{\Delta g}}{g} = \frac{{\Delta l}}{l} + \frac{{2\Delta T}}{T}$ 
Now$,$ $g$ is most accurate in the case in which error in $g\left( {l.e\,\Delta g} \right)$ is minimum$.$ In case $B,$ number of repetitions to perform the experiment is maximum and ${\Delta g}$  is minimum$.$
Hence,
option $(B)$ is correct answer.

Multiple choice physics measurements and units summary of si units fundamental quantities system of units

The SI unit of gravitational potential is :

  1. Joule/kg
  2. Joule$^2$/kg

  3. kg/Joule
  4. Joule/kg$^2 $
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The gravitational potential at a point is the potential energy associated with a unit mass due to its position in the gravitational field of another body. Gravitational potential is the amount of work done in bringing a body of unit mass from infinity to that point.
Gravitational potential (V) $=\dfrac{Work done}{Mass}=\dfrac{W}{m}$
Gravitational potential  is a scalar quantity and the  SI unit is $J/kg$.