A full wave rectifier circuit with diodes (D1) and (D2) is shown in the figure. If input supply voltage Vin=220sin(100π t) volt,…

Question

A full wave rectifier circuit with diodes (D1) and (D2) is shown in the figure. If input supply voltage Vin=220sin(100π t) volt, then at t=15 msec:

1. A. D1 is forward biased, D2 is reverse biased
2. B. D1 is reverse biased, D2 is forward biased (Correct answer)
3. C. D1 and D2 both are forward biased
4. D. D1 and D2 both are reverse biased

Correct Answer

Option B — D1 is reverse biased, D2 is forward biased

Detailed Solution & Explanation

The correct answer is $D_1$ reverse biased, $D_2$ forward biased.

Key Points

• At $t=15$ ms, phase $=100\pi\times0.015=1.5\pi$ rad, so $V_{in}=220\sin(1.5\pi)=-220$ V (negative half-cycle).
• In a centre-tapped full-wave rectifier, during the negative half-cycle the diode connected to the terminal that goes negative is reverse biased and the other conducts.
• Hence $D_1$ is reverse biased and $D_2$ is forward biased.