A diode has Zener voltage of $10$ V and maximum power dissipation of $0.5$ W, then the minimum resistance to be used in series with this diode for safety when it is connected to a $25$ V power supply is ______ $\Omega$.
Numerical value type. Enter your answer.
Answer: 300
Concept. Maximum safe current $I=\dfrac{P}{V_z}$; the series resistor drops the rest of the supply.
Step 1. Current. $\dfrac{0.5}{10}=0.05$ A.
Step 2. Resistance. $\dfrac{25-10}{0.05}=300$ Ω.
Answer. $300$.
Solution by Sreeraj P, M.Sc Physics


