Need help with this magnetic feild problem. Answer is there, just need it worked

Question

Need help with this magnetic feild problem. Answer is there, just need it worked out.

A uniform magnetic field B is set up in a solenoid of radius a = 0.40 m. B is directed out of the plane of the paper, and is increasing at a constant rate of +0.5 T/s. A conducting ring with resistance 10.0 ohm and radius b = 0.90 m encircles the solenoid, with the center of the ring on the axis of the solenoid. What is the size of the current induced in the metal ring? Ans. 25.1 mA What is the direction of the induced current in the ring? Explain clearly. Ans. clockwise

Explanation / Answer

Magnetic field inside a solenoid = mu*nI
Now, rate of change of the field = 0.5 T/s
Rate of change of flux = 0.5*pi*0.4^2 = 0.2512

EMF induced in the ring = 0.2512 V
a. V = IR
I = 0.2512/10 = 25.12 mA

b. Induced emf is in the opposite direction as determined by right hand rule for increasing fulx, because emf = -d(phi)/dt
Hence, for increasing B out of paper, the conventional right hand rule gives counterclockwise potential, -ve of which is clockwise potential
hence clockwise current

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