Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 11-science Answered

Hello Mam Define Young’s Modulus of elasticity. How much force is required to have an increase of 0.4% in the length of a metallic wire having a radius of 0.2mm. Y = 9.1 x 1010 Nm^–2 Please solve this sum
Asked by seeni2005 | 11 Jan, 2021, 09:11: PM
answered-by-expert Expert Answer
The ratio of tensile (or compressive)stress (σ) to the longitudinal strain (ε ) is defined asYoung’s modulus
and is denoted by the symbol Y.
 
Y = σ / ε   ........................ (1)
 
Tensile stress σ  is tensile force F per crosssection area A . 
 
σ = ( F / A )  ......................... (2)
 
Longitudinal strain ε is ratio of change in length ΔL to initial length .
 
ε = (ΔL/L)   ........................ (3)
 
Hence we get Young's modulus Y as
 
Y = (F/A)/(ΔL/L)= (F × L) /(A × ΔL)   ........................ (4)
--------------------------------------------------------------
 
Required force F to get 0.4% change in length of metallic wire of radius 0.2 mm is determined from eqn.(4) 
 
F = Y × A × ( ΔL / L )
 
crosssection area = π r2 = π × 0.2 × 0.2 × 10-6 = 1.257 × 10-7 m2 
 
If change in length is 0.4 %  , then ( ΔL / L ) = 0.004 = 4 × 10-3
 
F = 9.1 × 1010 × 1.257 × 10-7 × × 10-3 = 45.75 N

Answered by Thiyagarajan K | 11 Jan, 2021, 10:06: PM
CBSE 11-science - Physics
Asked by sumedhasingh238 | 28 Mar, 2024, 11:10: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by roshnibudhrani88 | 23 Mar, 2024, 05:52: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rosysahu678 | 02 Mar, 2024, 06:09: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by vaddevenkatesulu56 | 26 Feb, 2024, 09:02: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rustampathan | 25 Feb, 2024, 06:39: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 11-science - Physics
ans
question image
Asked by hjha9709 | 25 Feb, 2024, 12:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×