Question

if resistance increases by 20percent find percentage change in current​

Answer 1

Answer:

Given,

Initial resistance R1=ρA1L1=10Ω

New length after stretch is L2=1.25L1

For constant volume

V=A1L1=A2L2

Hence,

A2A1=L1L2=1.2

⇒A2=1.2A1

Where,

V= Volume

A= Area

L=Length

New resistance of stretched wire,

R2=ρA2L2=ρA1/1.21