Question

Two wires of same length and same area of cross-section but made of different materials of resistivities \( \rho_1 \) and \( \rho_2 \) are connected in series. The equivalent resistivity of the combination is :

• A. \(\dfrac{1}{2}(\rho_1+\rho_2)\)
• B. \(\rho_1+\rho_2\)
• C. \(\rho_1\rho_2\)
• D. \(2(\rho_1+\rho_2)\)

Hint:

For wires connected end-to-end (series combination), first find the equivalent resistance and then compare it with \(R=\rho L/A\). Remember that resistivity is a material property and does not simply add like resistances.

Answer 1

The Correct Option is A