EasyPhysicsMagnetic field
+4 / -1
Magnetic flux (in weber) in a closed circuit of resistance 20 Ω varies with time t(s) as φ = 8t² − 9t + 5. The magnitude of the induced current at t = 0.25 sec will be ____ mA.
A
150
B
300
C
250
D
200
Explanation
I = |dφ/dt| / R dφ/dt = 16t − 9 At t = 0.25: = 4 − 9 = −5 I = 5/20 = 0.25 A = 250 mA
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