PhysicsChapter 6: Alternating Current
Sinusoidal AC Voltage and Current
A sinusoidal alternating current or voltage
Definition
A sinusoidal alternating current or voltage changes with time according to a sine or cosine function.
Instantaneous Value
An ideal sinusoidal voltage can be represented as: v = V₀ sin(ωt) Similarly: i = I₀ sin(ωt) where: `V₀` = peak voltage `I₀` = peak current `ω` = angular frequency `t` = time. Angular frequency is: ω = 2πf Therefore: ω = 2π/T A complete cycle corresponds to: 2π radians = 360° At any instant `t`, the equation gives the voltage or current existing at that particular moment.
Positive and Negative Half-Cycles
Positive sign represents one chosen direction. Negative sign represents the opposite direction.
Formula / Key Relation
**v=V₀sin(ωt) i=I₀sin(ωt) ω=2πf**
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Sinusoidal AC Voltage and Current
Sticky Notes · Quick Revision
Sinusoidal AC:
- `v=V₀sinωt`
- `i=I₀sinωt`
- `ω=2πf`
60-second revision
- Sinusoidal AC varies smoothly according to a sine function.
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.