Below is a diagram showing two solenoids placed along the sa

Below is a diagram showing two solenoids placed along the same axis. The switch in the left solenoid\'s circuit is initially open. Just after the switch on the left coil is closed, does the current flow right to left, left to right through the resistor of the right coil, or is the current zero? Justify. Long after the switch on the left coil is closed, does the current flow right to left, left to right through the resistor of the right coil, Or is the current zero? Explain. The figure to the right show to inductors with their values printed next to them. The plus and minus signs indicate then voltage polarity. Which of the two inductors has the larger current flowing through it? Which inductor the current is changing most rapidly? If the current through either of the two inductors is. Sowing upward, is this current through that inductor increasing or decreasing?

Solution

1.

a)

Right to left

The Magnetic field originally is left to right through both the coils and right when switch closes the flux is increasing .So Magnetic field is right to left through the right coil.

b)

The Current is zero since the magnetic filed and flux throught the right coil is not changing

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2.

a)

Voltage across inductor is given by

V_L=-L(dI/dt)

With Voltage across inductor V_L and Inductance L Known then we can find rate of change of current..So we cannot find current I flowing through the inductor.

b)

For Left inductor

dI/dt =2/(2*10^-3) =1000 A/s

For RIght Inductor

dI/dt =4/(1*10^-3) =4000 A/s

Yes ,through the Right inductor with L=1 mH

c)

The Current is decreasing since dI/dt<0 ,then V_L>0 and the input side is more negative .The potential increases in the direction of the current.