COMEDK20269 May 2026Morning ShiftPhysicsSemiconductorsActual
In the circuit given, the reverse breakdown voltage of the Zener diode is 4.8 V. The current through the Zener and the power dissipation in Zener is:
Options
- A12.4 mA ; 97.52 mW
- B2.88 mA ; 13.82 mW
- C22.4 mA ; 107.52 mW
- D28.8 mA ; 138.24 mW
Correct answer
C. 22.4 mA ; 107.52 mW
Step-by-step solution
Given: Input voltage, V = 12 V Zener voltage, V_z = 4.8 V Series resistance, R_s = 250 Load resistance, R_L = 750 First, we check if the Zener diode is in the breakdown region. The voltage across the load without the Zener diode is: V' = R_L R_s + R_L V = 750 250 + 750 12 = 9 V Since V' > V_z , the Zener diode is in breakdown and the voltage across the load is clamped at V_z = 4.8 V . The current through the series resistor R_s is: I = V - V_z R_s = 12 - 4.8 250 = 7.2 250 = 0.0288 A = 28.8 mA The current through th