Question

Assertion (A) : Meterbridge wire is made up of manganin.
Reason (R) : The temperature coeffiecient of resistance is very small for manganin.

• A. Both A & R are true and R is the correct explanation of A
• B. Both A & R are true and R is not a correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Answer 1

Answer: (A)

Both A & R are true and R is the correct explanation of A

The bridge wire is made up of manganin because it have large resistivity and it's resistivity is nearly constant over large values of temperature.

The temperature coefficient of manganin is very small. Thats why it's resistivity is nearly constant over large value of temperature which is exactly required for bridge wire.

Hence assertion is correct and reason is correct and the reason is the correct explanation of the assertion.