In a coil of resistance `100 Omega` , a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is

Options

A. `200 Wb`
B. `225 Wb`
C. `250 Wb`
D. `275 Wb`

Answer

c

Explanation

Emf induced can be written as : `epsi = (Delta phi)/(Delta t)`
Average current can be written as : `I_(av) = epsi/R = 1/R (Delta phi)/(Delta t)`
Charge flown through the coil can be written as:
`Delta q = I_(av) Delta t = (Delta phi)/R`
`rArr Delta phi = R xx Delta q`
` rArr Delta phi = R xx ` area under current time graph
`rArr Delta phi = 100 xx (1/2 xx 10 xx 0.5) = 250 Wb`
Hence option (c ) is correct.