Question

A pair of adjacent coils has a mutual inductance of 80 mH. If the current in one coil changes from 10 A to 25 A in a time of 1.5 s, the change of flux linked with the other coil is:

• A. \(0.6 { Wb}\)
• B. \(1.8 { Wb}\)
• C. \(1.2 { Wb}\)
• D. \(0.8 { Wb}\)

Hint:

Remember, the flux linkage change due to mutual inductance can be calculated directly from the product of mutual inductance and the change in current.

Answer 1

The Correct Option is C

Step 1: Convert mutual inductance to Henrys. Mutual inductance \( M = 80 { mH} = 80 \times 10^{-3} { H} \). 
Step 2: Calculate the change in current. The current change \( \Delta I = 25 { A} - 10 { A} = 15 { A} \). 
Step 3: Calculate the change in flux \( \Delta \Phi \) linked with the other coil. \[ \Delta \Phi = M \times \Delta I = 80 \times 10^{-3} { H} \times 15 { A} = 1.2 { Wb}. \]