Question

A p-n junction diode connected in series with a resistor of 200 is forward biased so that a current of 200 mA flows
If the voltage across this combination is instantaneously reversed at 10, the current through diode is approximately,
A) 400 mA B) 200 mA C) 100 mA
D) O mA
DAC
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Answer 1

answer : option (B) 200mA

A p -n junction diode is connected in series with a resistor of 200 ohm is forward biased so that a current of 200mA flow through it.

now, the voltage across the combination is instantaneously reversed at t = 0 , diode becomes short circuit. means, current through diode = current through resistor.
first of all, find voltage across the circuit, V = 200 ohm × 200 mA = 40 volts
here, resistance of resistor, R = 200 ohm,

using Ohm's law, I = V/R

so, I = 40/200 = 200mA

hence, answer should be 200 mA .