(i) Refer to Fig. 3.4 (i). The conventional current coming out of battery flows in the branch circuits. In diode D1, the conventional current flows in the direction of arrowhead and hence this diode is forward biased. However, in diode D2, the conventional current flows opposite to arrowhead and hence this diode is reverse biased.
(ii) Refer to Fig. 3.4 (ii). During the positive half-cycle of input a.c. voltage, the conventional current flows in the direction of arrowhead and hence diode is forward biased. However, during the negative half-cycle of input a.c. voltage, the diode is reverse biased.
(iii) Refer to Fig. 3.4 (iii). During the positive half-cycle of input a.c. voltage, conventional current flows in the direction of arrowhead in D1 but it flows opposite to arrowhead in D2. Therefore, during positive half-cycle, diode D1 is forward biased and diode D2 reverse biased. However, during the negative half-cycle of input a.c. voltage, diode D2 is forward biased and D1 is reverse biased.
(iv) Refer to Fig. 3.4 (iv). During the positive half-cycle of input a.c. voltage, both the diodes are reverse biased. However, during the negative half-cycle of input a.c. voltage, both the diodes are forward biased.
Wilfykil answered the question on August 14, 2019 at 06:25