# Current in Circuit with Emf, Resistor & Capacitor

• swechan02
In summary, the current of the circuit with an emf of -5V, a 5ohm resistor, and a 20 F capacitor depends on the type of circuit and whether the emf is constant or varying. The capacitor will block the DC current after a certain amount of time and may also complicate the circuit if the supply is AC. The effect on current will vary depending on the setup of the circuit.
swechan02
If there is a circuit with--Emf -5V and one 5ohm resistor and one 20 F capacitor, what is the current of the circuit?
Will there be any effects on current because of capacitor?

swechan02 said:
If there is a circuit with--Emf -5V and one 5ohm resistor and one 20 F capacitor, what is the current of the circuit?
Will there be any effects on current because of capacitor?

It depends on whether the emf is constant and how the resistor and capacitor are connect to the source. In all cases I can think of, the capacitor affects the current when a steady emf is first applied. After some time, it either has no effect, or it keeps current from flowing. If the emf is varying in time, it's a whole different problem.

futb0l said:
The capacitor will block the DC Current after a certain amount of time. If the supply is AC then it will be more complicated.

It will block the current through the capacitor, but not the current through the emf source and the resistor unless it is a series circuit. That has not been specified.

## What is current in circuit with EMF, resistor, and capacitor?

The current in a circuit refers to the flow of electric charge, typically measured in amperes (A). In a circuit with an EMF (electromotive force), resistor, and capacitor, the current is affected by the resistance and capacitance of the circuit.

## How does a resistor affect current in a circuit?

A resistor is a component in a circuit that resists the flow of electric current. This means that it reduces the amount of current that can flow through the circuit. The higher the resistance, the lower the current will be. The relationship between resistance and current is described by Ohm's law (I = V/R), where V is the voltage and R is the resistance.

## How does a capacitor affect current in a circuit?

A capacitor is a component in a circuit that stores electric charge. When a capacitor is connected to a circuit with an EMF, it initially allows a large flow of current as it charges up. But as it becomes fully charged, it blocks the flow of current, limiting the amount of current in the circuit. The relationship between capacitance and current is described by the formula I = C(dV/dt), where C is the capacitance and dV/dt is the rate of change of voltage.

## What is the difference between direct current (DC) and alternating current (AC)?

Direct current is a type of current that flows in one direction, while alternating current periodically reverses direction. In a circuit with an EMF, resistor, and capacitor, DC will have a constant current flow, while AC will have a varying current flow due to the changing voltage from the EMF.

## How does the frequency of an AC current affect the behavior of a capacitor?

The frequency of an AC current describes how many times the current changes direction per second. The higher the frequency, the faster the current changes direction and the less time the capacitor has to charge up. As a result, a higher frequency AC current will result in a smaller current flow through a capacitor compared to a lower frequency AC current.

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