Question

Which of the following is not a valid reason for using alloys to make standard resistors?

(a) Alloys have a high value of resistivity

(b) They are least affected by air and moisture

(c) Alloys have a large temperature coefficient

(d) Their contact potential with copper is small

I got this question in an internship interview.

The query is from Current Electricity in section Current Electricity of Physics – Class 12

Answer 1

Right answer is (c) Alloys have a large temperature coefficient

To explain: Alloys have a high value of resistivity. They have a very small temperature coefficient. So their resistance does not change appreciably even for several degrees rise of temperature. That leaves the answer – alloys have a large temperature coefficient.