Question

The electrical resistivities of three materials P, Q and R are given below:

P	2.3 × 103 Ω m
Q	2.63 × 10−8 Ω m
R	1.0 × 1015 Ω m

Which material will you use for making

1. electric wires
2. handle for soldering iron, and
3. solar cells?

Give reasons for your choices.

Answer 1

1.  For making the electric wires, Q = 2.63 × 10⁻⁸ Ω m can be used, as this material has a very low resistivity.
2. For making the handle for the soldering iron, R = 1.0 × 10¹⁵ Ω m can be used, as this has a very high resistivity.
3. For making the solar cells, P = 2.3 × 10³ Ω m can be used, as this material is a semiconductor.