The correct answer is: A. known inductance and resistance.
An Anderson bridge is a type of bridge circuit used to measure inductance. It consists of four arms, two of which are known inductances and two of which are known resistances. The unknown inductance is placed in one of the unknown arms, and the bridge is balanced by adjusting the values of the known inductances and resistances.
The Anderson bridge is a very accurate method of measuring inductance, and it is often used in laboratory settings. It is also used in some commercial applications, such as in the testing of inductors for use in power supplies.
Here is a brief explanation of each option:
- Option A: known inductance and resistance. This is the correct answer, as explained above.
- Option B: known capacitance and resistance. This is not the correct answer, as capacitance is not used in an Anderson bridge.
- Option C: known resistance. This is not the correct answer, as resistance is only one of the two known values used in an Anderson bridge.
- Option D: known inductance. This is not the correct answer, as inductance is only one of the two known values used in an Anderson bridge.