In a voltage regulating circuit, a Zener diode with a breakdown voltage of 10 V is connected in parallel with a load resistor of 1 k . The input voltage to the circuit is a DC source of 20 V connected in series with a resistor of 200 . The current flowing through the Zener diode is:

Step-by-step solution

The input voltage V_ in = 20 V is greater than the Zener breakdown voltage V_Z = 10 V . Therefore, the Zener diode is in the breakdown region and acts as a constant voltage source of 10 V . The voltage across the load resistor R_L is equal to the Zener voltage V_Z = 10 V . The current through the load resistor is: I_L = V_Z R_L = 10 1000 A = 10 mA The voltage drop across the series resistor R_s is: V_s = V_ in - V_Z = 20 - 10 = 10 V The total current supplied by the source (which flows through R_s ) is: I_ total =