Learn

Friday, 9 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 16 March 2021, Shift 2, Physics Q17

Question 17 of 90 in this shift, Physics question 17 of 30, Section A.

In order to determine the Young's Modulus of a wire of radius 0.2 cm (measured using a scale of least count = 0.001 cm) and length 1m (measured using a scale of least count = 1 mm), a weight of mass 1 kg (measured using a scale of least count = 1 g) was hanged to get the elongation of 0.5 cm (measured using a scale of least count 0.001 cm). What will be the fractional error in the value of Young's Modulus determined by this experiment ?
  1. (1)1.4 %Official answer
  2. (2)0.9%
  3. (3)0.14%
  4. (4)9%

Official answer

Option 1

NTA final key.

Chapter
Units and Measurements
Topic
Elasticity
Idea tested
Error Analysis in Searle's Experiment

Same idea in other shifts

Asked 3× in all
  1. 2 Apr 2026, Shift 1 · Q27The diameter of a wire measured by a screw gauge of least count 0.0010.001 cm is 0.080.08 cm. The length measured by a scale of least count…MediumSingle correct
  2. 8 Apr 2024, Shift 1 · Q48Young's modulus is determined by the equation given by Y=49000mldynecm2Y=49000\frac{m}{l}\frac{\mathrm{dyne}}{\mathrm{cm}^2} where MM is the mass and…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.