I've been asked to use the ideal diode model on the circuit below to determine the values of I and V.
To determine which diodes were on or off, I considered each possible case:
- D1 and D2 are both off. This can't be the case because when both diodes are off, they each have positive voltages applied to them which would indicate that they should both be on. This contradicts the original assumption.
- If D1 and D2 are both on, I get that V = 0V and I = -0.25mA.
- If D1 is on and D2 is off, a positive voltage is applied to D2 meaning that it should actually be on.
- If D1 is off and D2 is on, I get V = -1V and I = 0A.
Which one's correct? Case 2 or case 4?