There exists a uniform magnetic field B=Botk in a region. A circular conducting loop of radius r and resistance R is placed with its plane in x-y plane. Determine the current through the loop and tension at time t developed in the loop as a result of induced current.

According to given question the change in magnetic field with respect to time produce flux and with time the flux through the circular coil increases  hence a induced current will be developed in clockwise and its magnitude is equal to 
e = -dφdt= -d(B.ds)dt =-dB .dsdt  (negative sign shows induced emf opposes the change in flux) i =eR  = -dB .dsR dt = -dB .πr2R dti = d(B0t)πr2R dt = B0πr2R
the vaule of tension is the force acting on the wire when placed in magnetic field 
hence T = BIL
dTdt = d(B0t)B0πr2LRdt=B02πr2LR  (putting value of i)T(t)  =B02πr2×2πrR =B022π2r3R .
​hence the tension is developed since the magnetic field is non uniform and changes with time .
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