Question

A wire is bent to form the double loop as shown in the figure. There is a uniform magnetic field directed into the plane of the loop. If the magnitude of this field is decreasing, the current will flow from

• A. A to B and C to D
• B. B to A and D to C
• C. A to B and D to C
• D. B to A and C to D

Answer 1

The correct option is C A to B and D to C

According to Faraday's law emf induced, $E=-\frac{d\varphi }{dt}$
This induced emf will oppose the rate of change of flux due to change in the magnetic field.
As magnetic field is decreasing, current will be induced in such a way that it tries to increase the magnetic field. Since change in flux for AB is more as compared to inner loop, therefore current in AB will decide the net magnetic field due to induced emf. The direction of current in AB should be from A to B so that net magnetic field due to induced emf will be inwards. Since for outer loop direction of current is from A to B, hence for inner loop it will be from D to C.