Ques. 1AIPMT 2001
The current in the circuit will be [figure]
- 540 A
- 550 A
- 510 A
- 520 A
Answer
(2) 550 A
Solution
The long plate (positive terminal) of the 5 V cell is on the left, so current leaves the cell towards the left junction and flows from left to right through the upper branches.
Diode D2 points from left to right ⇒ it is forward biased and conducts (ideal diode, zero resistance).
Diode D1 points from right to left ⇒ it is reverse biased, so no current flows through the upper 20 branch.
∴ Total resistance in the circuit = 20 + 30 = 50
⇒ I = VR = 550 A
Answer: (2)