A sinusoidal alternating electromotive force (emf) is generated by rotating a coil of…
PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A sinusoidal alternating electromotive force (emf) is generated by rotating a coil of a generator at a constant angular speed.
(i) Write the mathematical expression for the instantaneous emf in terms of its peak value and angular frequency.
(ii) Define the term "phase angle" for an alternating voltage and briefly explain its physical significance.
(iii) Show that a phase difference of ϕ radians between two sinusoidal voltages of frequency f corresponds to a time difference Δt=2πfϕ.