Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils.
Reason R: Constantan and manganin have very small value of temperature coefficient of resistance.
In the light of the above statements, choose the correct answer from the options given below.

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

Answer 1

The Correct Option is A

To determine the correct option for the given statements:

1. Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils.
2. Reason R: Constantan and manganin have a very small value of the temperature coefficient of resistance.

The assertion states that alloys like constantan and manganin are used in making standard resistance coils. This is true. These alloys are known for their stable resistive properties, even with changes in temperature.

The reason provides an explanation for the assertion. It claims that constantan and manganin have a very small temperature coefficient of resistance. This is indeed true and scientifically accurate. The temperature coefficient of resistance determines how much the resistance of a material changes with temperature. A small coefficient means that the resistance changes very little, providing stability, which is desirable when creating standard resistors that need to maintain a consistent resistance value regardless of temperature fluctuations.

Since both the assertion and the reason are true, and the reason accurately explains why these alloys are used in making resistance coils, the correct option is:

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