In a coil of resistance 50 W, the induced current developed by changing magnetic flux through it, is shown in figure as a function of time. The magnitude of change in flux through the coil is

Options

A. 10 Wb
B. 20 Wb
C. 32 Wb
D. 40 Wb

Answer

A

Explanation

According to the given graph (I - t ) induced current (I ) is obtained from the slope.
Hence `l =(1)/(R ) (dphi)/(R ) (d phi)/(dt)`
`implies d phi = I dt .R ` = area of triangle `POS xx R = (8xx 0.2 )/( 2) xx 50 = 40 ` Wb