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⚛️ Physics  ·  Units and Measurements  ·  NEET & JEE

The period of a pendulum is T = 2π√(L/g). If L is measured with 2% error and g with 3% error, the maximum percentage error in T is:

Answer: 2.5%.

  • A 5%
  • B 0.5%
  • C 1.5%
  • D 2.5%

Correct answer: D. 2.5%

Explanation: T depends on L and g each to the power 1/2, so the fractional error is halved: error in T = (1/2)(2% + 3%) = 2.5%.

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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