Question

The resistance of a conductor of length 75 cm is 3.25 Ω. Calculate the length of a similar conductor whose resistance is 13.25 Ω.

Answer 1

l₁ = 75 cm; R₁ = 3.25 Ω; R₂ = 13.25 Ω; l₂ = ?

For a similar conductor, resistance is directly proportional to length.

\[ \frac{\text{R}_{1}}{\text{R}_{2}}=\frac{l_{1}}{l_{2}}\]

\[l_{2}=\frac{\text{R}_{2}}{\text{R}_{1}} \cdot l_{1}\]

\[= \frac{13.25}{3.25} \times {75}\]

= 305.76 cm