Original resistance: [ R = \rho \frac{L}{A} = 20 \ \Omega ]
I have structured it exactly like an official NCERT Solutions answer: step-by-step, using the correct formulas, and ending with the final answer boxed. A wire of resistance 20 Ω is stretched to three times its original length. Calculate its new resistance. Assume the volume and resistivity remain constant. Solution: ncert solutions
We know the formula for resistance:
[ R' = 9 \times 20 \ \Omega = 180 \ \Omega ] Original resistance: [ R = \rho \frac{L}{A} =