In the given figure, a diode D is connected to an external resistance R = 100 Ω and an e.m.f. of 3.5 V. If the barrier potential developed across the diode is 0.5 V, the current in the circuit will be [figure]
- 20 mA
- 35 mA
- 30 mA
- 40 mA
Answer
(3) 30 mA
Solution
The diode is forward biased; a potential drop equal to the barrier potential (0.5 V) occurs across it.
Potential drop across R: VR = 3.5 - 0.5 = 3.0 V
I = VRR = 3.0100 = 0.03 A = 30 mA
Answer: (3)