AC Voltage Applied to A Resistor – AC Voltage, Equations, FAQs
AC Voltage Applied to a Resistor
In this section, we will deal with an electric circuit, where an AC
voltage is applied across a resistor. Before applying AC voltage across
the resistor, let us know what an alternating current (AC) is. Electric
current, which reverses its direction periodically and changes its
magnitude continuously with time, is known as an alternating
current.
AC Voltage Applied to a Resistor Derivation
Let us consider the circuit as shown below. We have a resistor and an AC
voltage V, represented by the symbol ~, that produces a potential
difference across its terminals that varies sinusoidally. Here, the
potential difference or the AC voltage can be given as
Here, v_{m }is the amplitude of the oscillating potential difference and the angular
frequency is given by ω.
As it works equally well for AC voltages and DC voltages. We saw that the
voltage across the resistor and the current passing through it are both
sinusoidal quantities and are represented by the graph shown in the figure
above. Both the quantities are in phase with each other.
The instantaneous power in the circuit is given by,

Frequently Asked Questions – FAQs
What is direct current?
The unidirectional flow of electric charges is known as
direct current.Does AC change its magnitude continuously with time?
Yes, alternating current changes its magnitude continuously
with time.Define frequency of the electrical signal.
The number of cycles per second is known as frequency.
Frequency is measured in hertz.Stay tuned with BYJU’S to learn more about the AC voltages, the
behaviour of the circuit when AC voltage is applied across a resistor
and much more.