Question

The relation between Voltage V (across the conductor) and current I through the conductor is given in the graph.

1. Which law establishes the relation between voltage and current?

2. A metal wire of resistivity 6.4 × 10^-5 ohm cm and length 1.98 m has a resistance of 7Ω. Find radius of wire

Answer 1

1. Ohms law

2. Resistance of wire R = \(\frac{ρl}{A}\)

R = \(\frac{ρl}{\pi r^2}\), r = \(\sqrt \frac{ρl}{\pi R}\)

r = \(\sqrt\frac{6.4\times10^{-5}\times1.98}{3.14\times7}\)

= 2 × 10^-3 m.