The circuit shown in the figure is used to provide regulated voltage (5 V) across the 1 kW resistor

Q. The circuit shown in the figure is used to provide regulated voltage (5 V) across the 1 kW resistor. Assume that the Zener diode has a constant reverse breakdown voltage for a current range, starting from a minimum required Zener current, IZ min = 2 mA to its maximum allowable current. The input voltage V_I 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

(A) 186 Ωand 10 mW                                  (B) 100 Ω and 40 mW

(C) 100 Ω and 10 mW                                  (D) 186 Ω and 40 mW

Ans: 100 Ω and 40 mW