Answer Happy

1. 2. 3. 4. Using ideal Zener diode approximations, find the minimum and maximum currents through the diode in Fig. 54.39. [4 mA, 8 mA] 2126 Tutorial Problems 54.1 [No] Is the ideal Zener diode shown in Fig. 54.36 properly biased? If not, explain why ? Check up if the diode in Fig. 54.37 is biased properly for normal operation. What is the current taken by the diode? [Yes : 4 mA] 12V Check up if Zener diode of Fig. 54.38 is reverse-biased as well as properly voltage-biased. Calculate diode current and power dissipation. [6 mA, 96 mW] Electrical Technology RIK ½-16 V Izmax=10 mA 12V I 5 K ► ww 60-80 V Iz 15 K REIK V₂-30 V Z V₂-8 V 1₂ max-5 mA Fig. 54.36 Fig. 54.37 Fig. 54.38 5. A 9 V stabilized voltage supply is required to run a car stereo system from car's 12 V battery. A Zener diode with V₂ = 9 V and Pmax = 0.25 W is used as a voltage regulator as shown in Fig. 54.40. IL IL I R ▶ ww 12V Fig. 54.39 Find the value of the series resistor R. 6. A load of IkW is connected across a 10 V Zener regula- tor as shown in Fig. 54. 41. The zener current can vary between 5mA to 55mA while maintaining the voltage constant. Find the minimum and maximum voltage level at input. (i) the value of series resistance required. (ii) diode current when the load is 1200 2 (Electronic Devices and Circuits, Nagpur Univ. Summer, 2004) 7. A 24V, 600 mW zener diode is used for providing a 24V stabilized supply to a variable load. If the input voltage is 32V, calculate 1K = 30 V ww Vin 2 K3 Iz V₂-9V Pmax 0.25 W Fig. 54.40 500 ww 10 V V-16 V Imax=10 mA Fig. 54.41 RL [120 Ω] IK (Electronics Engg., Bangalore Univ. 2003)