Diode in Parallel Circuit: Effects on Current Flow

[sanado]

What would happen if u had a circuit that was earthed at a point and it had an EMF of let's say 9V. If i had 1 resistor and immediately after that i had a resistor and diode in parallel, would any current enter the resistor. My understand is that it wouldn't since once the diode opens up, it effectively acts as a conductor of 0 resistance. With this being the base, does all the current pass into the diode?

 

[Chi Meson]

Your understanding is correct (the diode must be oriented in the correct manner, of course).

Keep in mind that we're talking "ideal" conditions. A diode is considered to have zero resistance in one direction and infinite resistance in the other. But in reality, nothing has truly zero, nor infinite resistance.

There would be a tiny current that goes through the resistor in parallel with the diode, but it is mostly insignificant. So you are "correct enough" for basic problems.

 

[Moetasim]

I can provide an explanation for the effects of a diode in a parallel circuit on current flow. In a parallel circuit, the current is divided among the different branches based on the resistance of each branch. In this case, the resistor and diode are in parallel, so the current will be divided between them.

If the circuit is earthed at a point and has an EMF of 9V, the current will flow from the positive terminal of the battery, through the resistor and diode branches, and back to the negative terminal of the battery. The amount of current that flows through each branch will depend on the resistance of the branch.

In the case of a diode, it has a very low resistance when it is forward biased (allowing current to flow) and a very high resistance when it is reverse biased (blocking current flow). So, when the diode is forward biased, it will act as a conductor with very low resistance and allow most of the current to flow through it. This means that very little current will pass through the resistor.

However, if the diode is reverse biased, it will act as an insulator with very high resistance and block most of the current from flowing through it. In this case, the majority of the current will pass through the resistor.

So, to answer your question, if the diode is forward biased, most of the current will pass through it and very little will enter the resistor. But if the diode is reverse biased, most of the current will pass through the resistor and very little will enter the diode. This is because the diode's resistance will change depending on its bias, and this will affect the current flow in the circuit.

In summary, in a parallel circuit with a resistor and diode, the amount of current that enters each branch will depend on the resistance of the branch and whether the diode is forward or reverse biased. The diode will act as a conductor or insulator, depending on its bias, and this will affect the current flow in the circuit.