Question

Select the unit of the coefficient of mutual induction from the following.

• A. volt second / ampere
• B. weber ampere
• C. ampere / weber
• D. volt ampere / second

Hint:

The coefficient of mutual induction is measured in volt-seconds per ampere because it relates to the induced flux in one coil per unit current in the other coil.

Answer 1

The Correct Option is A

The coefficient of mutual induction \( M \) between two coils is defined as the ratio of the flux linkage in one coil to the current in the other coil that produces the flux. It is given by: \[ M = \frac{\Phi_{21}}{I_1}, \] where: - \( \Phi_{21} \) is the flux linked with coil 2 due to the current \( I_1 \) in coil 1, - \( I_1 \) is the current in the first coil. The unit of flux (\( \Phi \)) is the weber (Wb), and the unit of current (\( I \)) is the ampere (A). Thus, the unit of mutual induction \( M \) is: \[ M = \frac{\text{weber}}{\text{ampere}} = \frac{\text{volt second}}{\text{ampere}}, \] because one weber is equal to one volt-second, and mutual induction involves the flux linkage, which is measured in volt-seconds per ampere. Thus, the unit of the coefficient of mutual induction is volt second / ampere, which corresponds to option (A).