Question

A wire of resistance 4 ohm is stretched to triple its length

Answer 1

we have a formula for resistance ie R=n2 R so length is stretched to 3 time so take square root on 3 so 9 and 4 is resistance so as will be 36 ohm

Answer 2

Answer:

36 ohm

Explanation:

R=P(L/A)

In first case,

R1=4ohm

L1=L

A1=A

In second case,

R2=R

L2=3×4=12L

A2=A

Solutions

R1/R2=( L1/L2)×(A1/A2)

4/R=(L/12L)×(A/A)

4/R=1/12

R=36 ohm