Interactive demonstration: three sliders control amplitude, frequency and phase of a live sine wave; the period readout updates as T = 1/f.
Three knobs describe every sine wave
s(t) = A sin(2πft + φ). Turn one knob at a time and watch what refuses to change.
Peak amplitude A
2.0 V
Height only. Loudness, brightness — never pitch.
Frequency f
5 Hz
Cycles per second. 0 Hz is allowed — that is DC.
Phase φ
0°
Where the first cycle starts. 360° = 2π rad = one full period.
Double f, halve T
90° head start
DC — f = 0
Mains socket (50 Hz)
The grey wave never moves: A = 2 V, f = 5 Hz, φ = 0°. Everything you do is measured against it.
Period
T = 1 / f
Phase in radians
φ × 2π / 360
Cycles on this screen
window = 0.5 s