Question

A resistor is made by winding a very long thin metal wire, insulated so adjacent coils do not touch. At room temperature, the resistance is 100 ohms.
If the resistor is then cooled to 77 K, the resistance:

A. changes only slightly, if at all.
B. increases significantly (more than a factor of two).
C. decreases significantly (more than a factor of 1/2).

Answer 1

Answer:

Option A

Explanation:

The correct answer is  Option A.

At room temperature, the resistance is equal to 100 ohms.

When the temperature is reduced to 77 K from room temperature, change in the resistance is very less.

The temperature coefficient of the resistivity of most of the metal is small for the metals which are approximately equal  0.01 /K.

hence, Change is only slightly.