In the figure, a wire and a 10 ohm resistor are used to form a circuit in the sh

Question

In the figure, a wire and a 10 ohm resistor are used to form a circuit in the shape of a square, 20 cm by 20 cm. A uniform but nonsteady magnetic field is directed into the plane of the circuit. The magnitude of the magnetic field is decreased from 2.40 T to 0.80 T in a time interval of 65 ms. The average induced current and its direction through the resistor, in this time interval, are closest to:

A) 98 mA, from b to a
B) 59 mA, from a to b
C) 150 mA, from a to b
D) 98 mA, from a to b
E) 59 mA, from b to a

Explanation / Answer

induced emf is defiend as the rate of change of magnetic flux
in mathematical form,
induced emf e = NAdB/dt
where A = area
N = no. of tunrs
dB/dt = rate of change of amgnetic flux

so emf e = 1* 0.2*0.2*(0.8-2.4)/0.065

emf e = -0.984 volts

so induced current i = e/R
where R = resisatnce

i = 0.984/10

i = 98 mA from b to a option A

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects