Draw a neat and labelled circuit diagram for a full wave rectifier.

Answer: [Diagram described] Full wave rectifier using a centre-tap transformer and two diodes.

[Figure: An a.c. input is applied across the primary of a step-down transformer. The secondary has a centre tap C. The top end A of the secondary is connected to the p-side (anode) of diode D₁, and the bottom end B to the p-side of diode D₂. The n-sides (cathodes) of D₁ and D₂ are joined together at point P. A load resistance R_L is connected between P and the centre tap C. The d.c. output is taken across R_L.]

Labels: a.c. input, transformer (primary, secondary with centre tap), D₁, D₂, load R_L, output.

Working: During the positive half cycle (A positive w.r.t. C), D₁ is forward biased and conducts while D₂ is reverse biased; current flows through R_L from P to C. During the negative half cycle (B positive w.r.t. C), D₂ conducts and D₁ is off; current again flows through R_L from P to C. Thus current flows through the load in the same direction in both half cycles, giving a pulsating d.c. output.