The 6 V zener diode shown in the figure, has zero zener resistance and a knee current of 5 mA. The minimum value of R so that the voltage across it does not fall below 6 V is \n\n[Figure needs to be uploaded later]
- A. 1.2 k ohms
- B. 80 ohms
- C. 50 ohms
- D. 0 ohms
Answer: B. 80 ohms
Explanation: [Figure needs to be uploaded later]\n$I = \frac{10 - 6}{50} = 80$ mA. $I_{zk} = 5$ mA. $I_{Lmax} = I - I_{zk} = (80 - 5) = 75$ mA. $R_{Lmin} = \frac{V_L}{I_{Lmax}} = \frac{6 V}{75 mA} = 80 \Omega$.