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
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ampere
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coulomb
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ohm
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volt
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meter
B
Correct answer
Explanation
This is the SI unit of Charge
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Newton
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Celsius
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Ampere
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Volt
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Ohm
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.
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.
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Decibel
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1cy (light year)
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1 parsec
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None of these
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.
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force
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work
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pressure
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light
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.
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Kelvin
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Celsius
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Fahrenheit
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none of the above
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.
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0.73
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0.83
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0.93
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None of these
B
Correct answer
Explanation
1 US gallon equals 0.832674 imperial gallons, approximately 0.83. The imperial gallon is larger than the US gallon.
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Ampere
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Joule
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Hertz
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Newton
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.
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Calorie
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Joule
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Degree
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Both 1 and 2
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.
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.
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joule
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watt
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pascal
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killo-watt
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.
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.
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Ampere
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Joule
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Hertz
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Newton
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.
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Ampere
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Kelvin
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Second
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Joule
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.
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Unit of wave length
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Unit of atmospheric pressure
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Unit of mass
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Unit of velocity
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.