Question

Question 31:
The electrical resistivities of four materials P, Q, R and S are given below :

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.

Lakhmir Singh Physics Class 10

Answer 1

Answer:

A) tungsten

B) copper

C) plastic

D)

Answer 2

Explanation:

Since we know that the resistivity of the the material is defined the resistance power against the electric current.

Assume the decreasing order of the resistivity as P,Q,R and S.

(a)Heating element of electric current used more current so ,resistivity must be low . So, material should be S.

(b)connecting wires of electric iron used small current so ,resistivity must be a little high .So, material should be Q and R.

(c)covering of connecting wires used zero current so ,resistivity must be high.So, material should be P.