1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# Steel wire of length 'L' at 40oC is suspended from the ceiling and then a mass 'm' is hung from its free end. The wire is cooled down from 40oC to 30oC to regain its original length ′L′. The coefficient of linear thermal expansion of the steel is 10−5/oC, Young's modulus of steel is 1011N/m2 and radius of the wire is 1 mm. Assume that L>> diameter of the wire. Then the value of 'm' in kg is nearly

A
3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
9
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A 3We know thatE=FA△LL⇒ΔLL=FAE......(i)AlsoΔLL∝αΔT.....(ii)from (i) and (ii)FAE=αΔT⇒mg=(αΔT)AE⇒m=gαΔTAE=10−5×10×π×10−6×101110=π≈3 So correct answer is a

Suggest Corrections
0
Join BYJU'S Learning Program
Related Videos
Hooke's Law
PHYSICS
Watch in App
Join BYJU'S Learning Program