Question

In a pair of adjacent coils, for a change of current in one of the coils from 0 A to 10 A in 0.25 s, the magnetic flux in the adjacent coil changes by 15 Wb. The mutual inductance of the coils is ________.
Fill in the blank with the correct answer from the options given below

• A. 120 H
• B. 12 H
• C. 1.5 H
• D. 0.75 H

Answer 1

The Correct Option is C

To find the mutual inductance (M) of the coils, we'll use the formula:

Φ = MI

Where:

• Φ is the change in magnetic flux
• M is the mutual inductance
• I is the change in current

However, we are given the rate of change of current (dI/dt) and the change in magnetic flux (dΦ/dt). We can use the formula:

dΦ/dt = M(dI/dt)

First, we need to calculate dI/dt:

dI/dt = (10 A - 0 A) / 0.25 s = 10 A / 0.25 s = 40 A/s

We are given dΦ = 15 Wb. We need to find dΦ/dt:

dΦ/dt = dΦ / dt = 15 Wb / 0.25 s = 60 Wb/s

Now, we can find the mutual inductance (M):

M = (dΦ/dt) / (dI/dt)

M = 60 Wb/s / 40 A/s

M = 1.5 H

Therefore, the mutual inductance of the coils is 1.5 H.

The correct answer is:

Option 3: 1.5 H