Consider the two circuits depicted below. The voltage source is the adjustable p
ID: 2113866 • Letter: C
Question
Consider the two circuits depicted below. The voltage source is the adjustable power supply similar to the one used in lab. The solenoid is considered to be ideal so that it has no internal resistance. The resistors in both circuits are the same: 5.0 Ohm.
The voltage of each power supply is increased at identical rates. While the voltages are being increased, which of the following is true about the currents through the power supplies?
Ileft greater than Iright
Ileft less than Iright
Ileft equal to Iright
The voltage is kept at 5.0 V for a long time. While the voltages are held constant, which of the following is true about the currents through the power supplies?
Ileft greater than Iright
Ileft less than Iright
Ileft equal to Iright
The voltage of each power supply is then decreased at identical rates. While the voltages are being decreased, which of the following is true about the currents through the power supplies?
Ileft greater than Iright
Ileft less than Iright
Ileft equal to Iright
I said less than, equal, and greater than. Could you please explain also?
Explanation / Answer
In FIRST MCT question, the correct response is the first one "I-left will be greater than I-right" as the inductor will act as a voltage source producing current in the opposite direction, SO I-right will be less, as the net source of emf in the circuit will be lesser, as long as the external voltage is increasing.
In SECOND MCT question, the correct response is the third one "I-left will be equal to I-right" as the inductor will not act as a voltage source as there is no change of magnetic flux through it because the external voltage has been held constant for a long time, and inductor is assumed tohave zero resistance.
In THIRD MCT question, the correct response is the second one "I-left will be less than I-right" as the inductor will act as a voltage source producing current in the same direction, SO I-right will be more, as the net source of emf in the circuit will be greater, as long as the external voltage is decreasing.