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⚛️ Physics  ·  Units and Measurements  ·  NEET & JEE

When adding the measured lengths 4.23 m, 1.2 m, and 0.234 m, the sum should be reported, following significant figure rules, as:

Answer: 5.7 m.

  • A 5.664 m
  • B 5.66 m
  • C 5.7 m
  • D 5.7640 m

Correct answer: C. 5.7 m

Explanation: In addition, the result can only be as precise as the least precise measurement (1.2 m, precise to one decimal place), so the sum 5.664 m must be rounded to 5.7 m.

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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