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 motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

Which quantities are measured in the same unit?

  1. energy, power and work

  2. energy and power, but not work

  3. energy and work, but not power

  4. power and work, but not energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Quantity             Dimension
Energy              $ML^2T^{-2}$
Work                  $ML^2T^{-2}$
Power                 $ML^2T^{-3}$

So, the dimension of energy and work is same but different to power.
Option (C) is correct.
Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

Which of the Quantity consists of unit as kg-m/sec ?

  1. Speed

  2. Momentum

  3. Acceleration

  4. Impulse
Reveal answer Fill a bubble to check yourself
B,D Correct answer
Explanation

1.  For Speed :

    $v = \dfrac{distance}{time} = m/sec$

2. For Momentum : 
   $P = m \times v$

   Units :  $kg - m/ sec$

3. For Acceleration :
    $a = \dfrac{\Delta v}{\Delta t}=m/{sec}^2$

4. For Impulse :
    $I =F\times \Delta t = \Delta p$
     Units : $N-sec  = (kg-m/{sec}^2) \times sec = kg-m/sec$

From above we can say that $Momentum$ and $Impulse$ have same unit as kg-m/sec.
      

Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

The unit kg $m^2s^{-2}$ is associated with

  1. Work

  2. Kinetic energy

  3. Potential energy

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$kgm^2s^{-2}$ is the unit of energy. It's dimension is $[ML^2T^{-2}]$ All the quantities given in the option are different form of energy. So their units will be same. Then the unit $kgm^2s^{-2}$ is associated with all of the options.

Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

Which of the following statements below should be followed while using the symbol for a unit of a physical quantity?

  1. The symbol named after scientist should have capital letter.

  2. They take plural forms.

  3. They can be written in full.

  4. They should be written only in the agreed symbols.
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

1. They symbol named after scientist should have the capital letter, 

2. They can be written in full 
3. They should be written only in the agreed symbols be used while using the symbol for a unit of a physical quantity. 
4. They cannot take plural forms.

Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

Unit of heat in S. I. system

  1. Watt

  2. Newton/ Meter

  3. Ergs / Sec

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

Heat is a form of energy that flow from a hotter body to a colder one.

S.I. unit of heat: Joul, Joule is defined as the amount of energy exerted when a force of one newton is applied over a displacement of one meter.
Option D.

Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

1 Kilocalorie $=$ ..................... joules.

  1. $4000$
  2. $5000$
  3. $4200$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Calorie is defined as the amount of heat energy needed to raise the temperature of one gram of pure water by one degree Celsius. $1$ Kilocalorie are $1000$ calories, the amount of caloric energy needed to raise the mass of$1$ kg of pure water by $1^0C$. $1$ kilocalorie is $4200$ Joules.

Option C. 

Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

Which of the following is not a characteristic of the standard unit?

  1. It should be of convenient size.

  2. It should change with respect to space and time.

  3. It should not be perishable.

  4. It should be easily reproducible.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Standard unit does not change with respect to time and space. Thus option B is correct.