WAEC Physics 2015 Theory — Question 6

Model answer

(a) This is the circuit of a half-wave rectifier. The diode allows current to flow (forward biased) for only one half of each complete cycle of the incoming a.c. supply, converting a.c. to a pulsating d.c. (b) Input voltage V1 is a full continuous sine wave. Output voltage V2 across the resistor R shows only the positive half-cycles - a series of humps with flat zero sections in between, corresponding to the intervals when the diode is reverse biased and no current flows.