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

The SI unit of latent heat is

  1. J/g

  2. J/kg

  3. J/kg K

  4. J/g K
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Latent heat is the amount of energy absorbed or released during a phase change per unit mass. Since it's energy per mass, the SI unit is joule per kilogram (J/kg). J/g K and J/kg K are units for specific heat capacity, which involves temperature change. Latent heat itself has no temperature component.

Multiple choice

The unit of power is

  1. Erg

  2. Watt

  3. Dyne

  4. Ohm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Power is the rate at which work is done or energy is transferred. The SI unit of power is the Watt (W), named after James Watt. One Watt equals one Joule per second. Erg is a unit of energy, Dyne is a unit of force, and Ohm is a unit of electrical resistance.

Multiple choice

Ampere hour is the unit of

  1. electrical energy

  2. electric potential

  3. electric current

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

Correct option is (4).

Multiple choice

What is the S.I. unit of potential difference?

  1. Volt

  2. Coulomb

  3. Ampere

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

The volt (V) is the SI unit of potential difference, defined as one joule per coulomb. Coulomb is the unit of electric charge. Ampere is the unit of electric current. Potential difference measures the work done per unit charge.

Multiple choice

P, Poise is a unit of

  1. surface tension

  2. viscosity

  3. area

  4. force
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Poise is a unit of viscosity.

Multiple choice

The unit for measuring the viscosity of a liquid is

  1. Dyne/ sq. cm

  2. Erg/ sec

  3. Centipoise

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

Centipoise is the standard unit for measuring viscosity, representing a fluid's resistance to flow. It equals 1/100 of a poise, which is the CGS unit for dynamic viscosity. Common liquids like water have low viscosity (around 1 centipoise), while honey has much higher viscosity.

Multiple choice

Kilowatt is a unit to measure

  1. force

  2. work

  3. power

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

Kilowatt (kW) is the standard unit for measuring power, equal to 1000 watts. Power is the rate at which work is done or energy is transferred. Option C is correct. Force is measured in newtons, work in joules, making options A and B incorrect.

Multiple choice

Which of the following options is unit of impulse?

  1. Steradian

  2. Newton-sec

  3. Pascal-sec

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

Impulse is defined as the product of force and time (J = F × Δt). Its SI unit is Newton-second (N·s), which is equivalent to kg·m/s. Steradian is a unit for solid angle, and Pascal-sec is not a standard unit for any physical quantity.

Multiple choice

The unit used to measure the depth of seas is

  1. kilometer

  2. fathom

  3. light year

  4. parsec

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A fathom is a nautical unit of depth equal to 6 feet (about 1.83 meters). It has been used for centuries to measure water depth for navigation and anchoring. Light years and parsecs measure astronomical distances, while kilometers are metric units.

Multiple choice

The units of which two are same?

  1. Momentum and Impulse

  2. Momentum and torque

  3. Momentum and angular momentum

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

It is correct as momentum = mass *velocity therefore unit is kg*m/sec, impulse =force*time. Therefore unit = (kg*m/sec*sec)*sec=kg*m/sec.

Multiple choice

Which of the following has the unit kg*m*m/sec*sec?

  1. Work done

  2. Kinetic energy

  3. Potential energy

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

Yes, all are correct as work done is a product of force exerted on the body and the distance moved by the body in the direction of the force. Its unit is kg*m*m/sec*sec. Kinetic energy is energy associated with motion of a body and is measured in kg*m*m/sec*sec. Potential energy is the energy stored in the body due to its position and is measured in kg*m*m/sec*sec.