Question

Following table gives the resistivity of a few samples at 200C:

Sample Resistivity (ohm-metre)

A 1.60x10 – 8

B 1.62x10 – 8

C 5.20x10 – 8

D 1.0x10 15

E 94.0x10 – 8

F 1.1x10– 6

Which material will you use for making

a) element of a heating device?

b) Connecting wires of electric iron?

c) Covering of connecting wires? (Give reason for your choice in each case)​

Answer 1

Answer:

a) answer is F

b) answer is A

c) answer is D

Explanation:

a) resistivity should be high but not insulator

b) least resistivity so that max conductance is present

c) max resistivity to stop current from flowing at all