Consider a conducting circular loop placed in a magentic filed as shown. When magnetic field changes with time, magentic flux also changes and emf is induced.
`e=-(dphi)/(dt)`
If resistance of loop is R then induced current.
`i=e/R`
For Current, charge must have come into motion. Magnetic force cannot make the statinoary charges to move. Actually there is an induced electric field in the conductor caused by changing magnetic flux, which make the change to move
`intvec(E).dvec(l)=e=-(dphi)/(dt)`
This induced electric field is non-electrostatic by nature. line integral of `vec(E)` around a closed path is non-zero

The magnetic field within cylindrical region whose cross - section is indicated starts increasing at a constant rate `alpha` tesla/sec The graph showing the variation.of induced electric field with distance r from the axis of cylinder is :

Options

A.
B.
C.
D.

Explanation

Explanation:
For rlt R `oint Edl=A(dB)/(dt)`
`E2pi r=(pir^(2))alpha`
`E=(ralpha)/2` or `Epropr`
So, E-r graph is a straight line passing through origin.
At r=R, `E=(Rlapha)/2`
for rgtR `E 2pir =(piR^(2))alpha`
Hence , choice (a) is correct and choices (b),(c) and (d) are wrong.