Question

In meter bridge experiment, to minimize an error due to contact resistance,

• A. use non-uniform meter bridge wire.
• B. repeat the experiment by interchanging the resistance in gaps.
• C. increase the current flowing through meter bridge wire.
• D. changing the value of known resistance in the gap.

Hint:

In meter bridge experiments, minimizing errors from contact resistance can be achieved by interchanging the resistances in the gaps.

Answer 1

The Correct Option is B

Step 1: Understanding the issue with contact resistance.
Contact resistance in a meter bridge can cause errors in measurements of resistance. To minimize this error, it is important to eliminate or reduce the effect of contact resistance.

Step 2: Analyzing the options.
- (A) Using a non-uniform meter bridge wire will introduce further errors, as the resistance along the wire will not be consistent. - (B) Repeating the experiment by interchanging the resistance in the gaps helps to minimize errors due to contact resistance because the contact resistance will affect both resistances equally, thus canceling out any error. - (C) Increasing the current flowing through the meter bridge wire may increase the effect of contact resistance. - (D) Changing the value of the known resistance in the gap does not eliminate contact resistance errors.

Step 3: Conclusion.
The best method to minimize errors due to contact resistance is to repeat the experiment by interchanging the resistances in the gaps. Thus, the correct answer is (B).