Correct Answer - D
We know that if the reverse bias is greater than the `V_(z)`, a breakdown condition is obtained, showing a sudden rise in the reverse current. In breakdown region, `V_(i)gtV_(z)`, for a long range of load `(R_(L))`, the voltage across `R_(L)` remains the same throgh the current may change. Therefore, portion de of the characteristics curve is relevant for the operation of zener diode as voltage regulator.
