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

Which is the unit of electric potential?

  1. Volt

  2. Ampere

  3. Joule

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

Volt is the SI unit of electric potential, named after Alessandro Volta. Electric potential represents the potential energy per unit charge. One volt equals one joule per coulomb. It measures the 'pressure' that drives electric current.

Multiple choice

Which of the following is the unit of frequency?

  1. Ampere

  2. Joule

  3. Hertz

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

Hertz (Hz) is the SI unit of frequency, defined as one cycle per second. It is named after the German physicist Heinrich Hertz who proved the existence of electromagnetic waves. Frequency measures the number of occurrences of a repeating event per unit of time.

Multiple choice

Which of the following is not a basic unit in the S.I. System?

  1. Ampere

  2. Kelvin

  3. Second

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

The SI base units are: meter (length), kilogram (mass), second (time), ampere (electric current), kelvin (temperature), mole (amount of substance), and candela (luminous intensity). Joule is a derived unit for energy/work (1 J = 1 kg·m²/s²), not a base unit.

Multiple choice

For which of the following is Bar used?

  1. Unit of wave length

  2. Unit of atmospheric pressure

  3. Unit of mass

  4. Unit of velocity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bar is a metric unit of atmospheric pressure. 1 bar equals 100,000 pascals or approximately 0.987 standard atmospheres. It's commonly used in meteorology and engineering to measure pressure.

Multiple choice

What is the full form of ALU?

  1. Arithmetic and light unit

  2. Arithmetic and logic unit

  3. Absolute logic unit

  4. Absolute light unit

  5. Absolute load unit
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is the correct full form of ALU.

Multiple choice

Unit of measuring electrical current is

  1. Ohm

  2. Volt

  3. Ampere

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

The ampere (A) is the SI unit of electric current, measuring the flow of electric charge. Ohm measures electrical resistance. Volt measures potential difference or voltage. Watt measures power (rate of energy transfer). Current is specifically measured in amperes.

Multiple choice

Which of the following statements is/are correct? a. The measurement is complete only if it shows the number and unit of measurement. b. The known fixed quantity is called measurement. c. The standard unit of measurement in use after revisions is the metric system.

  1. only a

  2. only b

  3. only c

  4. a and b

  5. b and c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the only correct statement. The measurement is considered complete only if it shows the number and unit of measurement.