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⚛️ Physics  ·  Units and Measurements  ·  NEET & JEE

Which of these is a dimensionless unit?

Answer: Radian.

  • A Newton
  • B Radian
  • C Pascal
  • D Watt

Correct answer: B. Radian

Explanation: The radian, used to measure plane angle, is dimensionless because it is defined as a ratio of two lengths (arc length / radius).

The 7 SI Base UnitsLengthmetre (m)fundamentalMasskilogram (kg)Timesecond (s)Electric Currentampere (A)Temperaturekelvin (K)Amount ofSubstancemole (mol)LuminousIntensitycandela (cd)Every other physical quantity is derived by combining powers of these 7 base units

The 7 SI base units. All derived units (newton, joule, watt, volt, etc.) can be expressed as combinations of these 7 fundamental units raised to various powers.

Concept context

SI base units, dimensional analysis, significant figures, and error propagation. The toolkit every physics calculation relies on.

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