The electrical resistivities of four materials P, Q, R, and S are given below: P: 6.84 × 10-8Ωm Q: 1.70 × 10-8Ωm R: 1.0 × 1015Ωm S: 11.0 × 10-7Ωm Which material will you use for making: a) heating element of electric iron b) connecting wires of electric iron c) covering of connecting wires Give reason for your choice in each case.

Vinay

3 years ago

Answer

a) An electric iron’s heating element is S, which has a high resistance. This is a nichrome substance.

b) An electric iron’s connecting wires are Q because they have a low resistance. Copper is the material in question.

c) The connecting wires are covered with R, which has a high resistance and is made of rubber.