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

Noise intensity is measured in ________ units.

  1. decimal

  2. decibal

  3. megabyte

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

Noise intensity is measured in decibels (dB). Note that the option provided contains a spelling error ('decibal' instead of 'decibel'), but it is the intended answer.

Multiple choice

One calorie of energy is equivalent to

  1. 0·42 joule

  2. 4·2 joule

  3. 42 joule

  4. 420 joule
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

One calorie is defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius, which is approximately 4.2 joules.

Multiple choice

The unit angstrom measures

  1. temperature

  2. electric current

  3. time

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

An angstrom is a unit of length equal to 10^-10 meters, commonly used to measure wavelengths of light and atomic distances.

Multiple choice

The SI unit for the amount of a substance is

  1. mole (mol)

  2. Kg

  3. gram

  4. milligram (mg)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  1. The amount of a substance that contains as many atoms, molecules, ions, or other elementary units as the number of atoms in 0.012 kilogram of carbon 12.
Multiple choice

The SI unit for force is

  1. Pascal (Pa)

  2. Newton (N)

  3. Dyne (dyn)

  4. Joule (J)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

2.  The SI unit of force is newton . A force of one newton will accelerate a mass of one kilogram at the rate of one meter per second per second.

Multiple choice

Kilowatt - hour is the unit for

  1. power

  2. electrical energy

  3. voltage

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

2  1 kWh is the amount of electrical energy consumed in 1 hour when the rate of consumption is 1000Joules/second

Multiple choice

Ampere is the SI unit for

  1. potential

  2. voltage (V)

  3. resistance (R)

  4. electric current (i)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

4, The SI unit of electric current

Multiple choice

The SI unit for luminous intensity is

  1. Candela

  2. Volt

  3. Watt

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

1 The candela is defined to be the luminous intensity of a light source producing single-frequency light at a frequency of 540 terahertz (THz) with a power of 1/683 watt per steradian, or 18.3988 milliwatts over a complete sphere cantered at the light source.

Multiple choice

The SI unit for energy is

  1. Joule (J)

  2. Candela

  3. Watt

  4. Watt/sec
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

1  the SI unit of work or energy is Joule (J), defined to be the work done by a force of one newton acting to move an object through a distance of one meter in the direction in which the force is applied.

Multiple choice

A light year is a unit for

  1. time

  2. speed of light

  3. length

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

3 The distance that light travels in a vacuum in one year, approximately 9.46 trillion (9.46 × 1012) kilometers or 5.88 trillion (5.88 × 1012) miles.