JEE Main 2021PhysicsMathematics in PhysicsMediumMCQ

JEE Main 2021 — Mathematics in Physics Question with Solution

JEE Main 2021 (01 Sep Shift 2)

Question

A student determined Young's Modulus of elasticity using the formula Y=MgL34bd3δ. The value of g is taken to be 9.8 m s-2 without any significant error, his observations are as following.

Physical Quantity

Least count of the Equipment used for measurement

 Observed Value
Mass (M) 1 g 2 kg
Length of bar (L) 1 mm 1 m
Breadth of bar (b) 0.1 mm 4 cm
Thickness of bar  (d) 0.01 mm 0.4 cm
Depression (δ) 0.01 mm 5 mm

Then the fractional error in the measurement of Y is :

Choose an option

Show full solutionCorrect option: D
Correct answer
D0.0155

Step-by-step explanation

Y=MgL34bd3δ

∆YY=∆MM+3∆l1+∆bb+3∆dd+∆δδ⇒∆YY=0.0005+3×0.001+0.0025+3×0.0025+0.002=0.0155

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Mathematics in Physics chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2021, covering the Mathematics in Physics chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.