A resistor of resistance 5.0 Ω is connected to an alternating-voltage source whose…
PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A resistor of resistance 5.0 Ω is connected to an alternating-voltage source whose instantaneous voltage is given by
V(t)=10sin(100πt)volts.
(i) Write the expression for the instantaneous current through the resistor.
(ii) Obtain an expression for the instantaneous power delivered to the resistor.
(iii) Determine the average power consumed by the resistor over one complete cycle of the alternating voltage, showing each mathematical step.
(iv) Calculate the numerical value of the average power.
(v) Sketch qualitatively on the same time axis the variations of the instantaneous voltage and the instantaneous power over two full cycles, labelling key points.