The circuit shown here is working as a 8 V dc regulated voltage source. When 12 V is used as input,

Question

The circuit shown here is working as a 8 V dc regulated voltage source. When 12 V is used as input, the power dissipated (in mW ) in each diode is (considering both zener diodes are identical) $\_\_\_\_$ .\

Professor PC Thomas Classes · Answer

(40) : Applying KVL on the loop, $-12+400 i+8=0$ or $i=0.01 \mathrm{~A}$\ So, power dissipated in each diode, $P=V I$\ or $P=4(0.01)=0.04 \mathrm{~W}=40 \mathrm{~mW}$\