Four different uniform and constant magnetic fields B→1=B0k^,B→2=2B0k^,B→3=3B0k^ and B→4=4B0k^ exist in first, second, third and fourth quadrant respectively of x-y plane as shown in figure. A square wireframe PQRS of one side I and total resistance R lying in x-y plane is moving with velocity v→=v0i^ such that its centre lies on x-axis and side PQ is parallel to x-axis. B0 and v0 are positive constants. Then the magnitude of current induced in the square loop at the instant its centre lies of origin is