Q 12-14-192JEE MainJEE Main 2019 (12 Apr, Shift 2)Easy
Figure shows a DC voltage regulator circuit, with a Zener diode of breakdown voltage $= 6$ V. If the unregulated input voltage varies between $10$ V to $16$ V, then what is the maximum Zener current?
Answer: (B) $3.5$ mA
The Zener current is largest at the largest input, $16$ V:
$$I_s = \frac{16 - 6}{2\ \text{k}\Omega} = 5\ \text{mA},\qquad I_L = \frac{6}{4\ \text{k}\Omega} = 1.5\ \text{mA}$$
$$I_Z = 5 - 1.5 = 3.5\ \text{mA}$$
Solution by Sreeraj P, M.Sc Physics