Question

The room-temperature electrical resistivities of pure lead and pure tin are 2.06 x 10-7 and 1.11 x 10-7 W*m, respectively. Select the best response that explains the resistivity of solid solution of tin in lead and lead in tin.

A. Adding slight amount of tin into lead will decrease the resistivity of lead.

B. Adding slight amount of lead into tin will increase the resistivity of tin.

C. Both A and B.

D. None of the above.

Answer 1

Electrical resistivity basically governs the current flow through solution. Higher the resistance, lower the current for same voltage.

As per data given in question, resistivity of pure lead is higher than resistivity of pure tin.

So if we add tin into lead then since pure tin has lower resistivity, overall resistivity of the lead solution must come down.

Similarly if add lead into tin then since pure lead has higher resistivity, overall resistivity of the tin solution will increase.

So correct option should be C. (Both A&B)