Question

A silicon diode is connected across a 3 V supply with a series resistance of 20 Ω. Neglecting diode resistance, calculate the diode current. *

Answer 1

Answer:

I= 0.115A

Explanation:

Here diode is forward biased with voltage =3−0=3V.

Vb=2

Vknee=0.7

Vb =Vknee + IR

3 = 0.7 + I.20

3-0.7= I.20

2.3/20=I

I= 0.115A

Answer 2

Given:

The voltage of the battery = 3 V

The resistance of the series combination = 20 ohm

To Find:

The value of the diode current.

Solution:

The resistance of an ideal diode is zero.

So, the total current in the circuit will go through the diode.

According to Ohm's law,

V = I × R

where V = voltage of the battery.

I = Total current in the circuit

R = Resistance of the circuit

⇒ 3 V = I × 20 ohm

⇒ I = 3 V/ 20 ohm = 0.15 A

Hence, the current through the diode is 0.15 Ampere.