devarshi-dt-logo

Question:

Figure shows a circular area of radius R where a uniform magnetic field →B is going into the plane of paper and increasing in magnitude at a constant rate. In that case, which of the following graphs, drawn schematically, correctly shows the variation of the induced electric field E(r)?

Solution:

Due to increasing magnetic field, induced electric field will be more as we move from center towards the periphery of circular area. However, after R, there is no magnetic field and therefore induced electric field decreases thereafter.