Physics · Science General

Units and Measurement

998 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
  1. Newton

  2. Celsius

  3. Ampere

  4. Volt

  5. Ohm

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

The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm. Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Resistance is measured in ohms.

Multiple choice
  1. Cm

  2. m

  3. Km

  4. None of these

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

The meter (m) is the SI (International System of Units) base unit for length. The SI system is the modern form of the metric system and provides standardized measurements used globally in science and everyday applications.

Multiple choice
  1. Decibel

  2. 1cy (light year)

  3. 1 parsec

  4. None of these

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

The decibel (dB) is the standard unit used to measure the intensity of sound. It's a logarithmic unit that expresses the ratio of a physical quantity (usually power or intensity) to a reference level.

Multiple choice
  1. force

  2. work

  3. pressure

  4. light

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

Pascal (Pa) is the SI unit of pressure, defined as one newton per square meter. Force is measured in newtons, work in joules, and light intensity in lumens or candelas. The pascal is commonly used to measure tire pressure, blood pressure, and atmospheric pressure variations.

Multiple choice
  1. Kelvin

  2. Celsius

  3. Fahrenheit

  4. none of the above

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

Kelvin is the SI base unit for thermodynamic temperature, named after Lord Kelvin. While Celsius and Fahrenheit are commonly used scales, Kelvin is the scientific standard starting from absolute zero.

Multiple choice
  1. 0.73

  2. 0.83

  3. 0.93

  4. None of these

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

1 US gallon equals 0.832674 imperial gallons, approximately 0.83. The imperial gallon is larger than the US gallon.

Multiple choice
  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, measuring the number of cycles per second. Ampere measures electric current, Joule measures energy, and Newton measures force.

Multiple choice
  1. Calorie

  2. Joule

  3. Degree

  4. Both 1 and 2

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

Both Calorie and Joule are valid units for measuring heat energy. Calorie (cal) is the traditional unit, specifically the amount of heat needed to raise 1 gram of water by 1°C. Joule (J) is the SI unit of energy, including heat energy. The conversion is approximately 1 calorie = 4.184 joules. Both are widely used in different scientific contexts.

Multiple choice
  1. Ohm

  2. Watt

  3. Newton

  4. Celsius

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

Celsius is indeed a unit of temperature measurement, part of the metric system. The other options are incorrect: Ohm measures electrical resistance, Watt measures power, and Newton measures force. Celsius scale sets water's freezing point at 0°C and boiling point at 100°C at standard atmospheric pressure.

Multiple choice
  1. joule

  2. watt

  3. pascal

  4. killo-watt

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

The pascal (Pa) is the SI unit for pressure, named after Blaise Pascal. It is defined as one newton per square meter. Joule is the SI unit of energy/work, while watt is the SI unit of power.

Multiple choice
  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
  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
  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
  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.