Question

A wire having length 2.0m, diameter 1.0 mm and resistivity 1.963 × 10^-8 Ω m is connected in series with a battery of emf 3 V and internal resistance 1. Calculate the resistance of the wire and current in the circuit.

Answer 1

Given, 

length (l) = 2m 

Diameter (D) = 1mm = 1 × 10^-3 m 

∴ radius (r) = \(\frac{D}{2}\) = 0.5 × 10^-3 m 

resistivity (f) = 1.963 × 10^-8 Ωm 

E = 3V Internal resistance (r) = 1 Ω 

R = ? I = ? 

We have,