Question

The electrical resistivities of five substances A, B, C, D and E are given below:

A	5.20 × 10−8 Ω m
B	110 × 10−8 Ω m
C	2.60 × 10−8 Ω m
D	10.0 × 10−8 Ω m
E	1.70 × 10−8 Ω m

1. Which substance is the best conductor of electricity? Why?
2. Which one is a better conductor: A or C? Why?
3. Which substance would you advise to be used for making heating elements of electric irons? Why?
4. Which two substances should be used for making electric wires? Why?

Answer 1

1. E is the best conductor of electricity because it has the least resistivity.
2. C is a better conductor than A because the resistivity of C is lower than that of A.
3. B can be used in the making of the heating elements of an electric iron because the resistivity of B is the highest.
4. C and E are the two substances that should be used for making electric wires because they have low electrical resistivities.