Question

A pair of adjacent coils has a mutual inductance of 2.5 H. If the current in one coil changes from 0 to 40 A in 0.8 s, then the change in flux linked with the other coil is

• A. 100 Wb
• B. 120 Wb
• C. 200 Wb
• D. 250 Wb

Answer 1

Answer: (A)

100 Wb

Answer 2

Given , $M = 2.5H,\frac{dI}{dt} = \frac{40 - 0}{0.8} = 50As^{- 1}$

Also, $\varepsilon = M\frac{dI}{dt} = \frac{d\varphi}{dt}$

Or $d\varphi = MdI = 2.5(40 - 0) = 100Wb$