Question 5 Page 209 - Chapter 12 Class 10 - Electricity

Use the data in Table 12.2 to answer the following –

(a) Which among iron and mercury is a better conductor?

(b) Which material is the best conductor?

Answer

(a) 

Resistivity of iron = 10 × 10 ^-8  

Resistivity of mercury = 94 × 10 ^-8

Resistance is directly proportional to the resistivity.

Higher the resistivity, the higher the resistance.

Hence, resistance of mercury is more than resistance of iron.

Since iron would provide lower resistance to the flow of current, iron is a better conductor.

(b) The substance which has the lowest resistivity is the best conductor.

Silver has the lowest resistivity.

Hence, silver is the best conductor.