A wire is stretched to increase its length by 4 times. The resistance of the wire will:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → increase by 16 times
The resistance (R) is
$R=ρ\frac{L}{A}$
$R'=ρ\frac{4L}{A/4}=16ρ\frac{L}{A}$
$\frac{R}{R'}=\frac{1}{16}$