The circuit shown in the figure is used to provide regulated voltage (5 V) across the 1 kΩ resistor. Assume that the Zener diode has a constant reverse breakdown voltage for a current range, starting from a minimum required Zener current, IZmin = 2 mA to its maximum allowable current. The input voltage VI may vary by 5% from its nominal value of 6 V. The resistance of the diode in the breakdown region is negligible.
The value of R and the minimum required power dissipation rating of the diode, respectively, are
1
186 Ω and 10 mW
2
100 Ω and 40 mW
3
100 Ω and 10 mW
4
186 Ω and 40 mW