A Zener of power rating 1 W is to be used as a voltage regulator

cbse
semiconductor

#1

A Zener of power rating 1 W is to be used as a voltage regulator. If Zener has a breakdown of 5 V and it has to regulate voltage which fluctuated between 3 V and 7 V, what should be the value of ${ R }_{ s }$ for safe operation as shown below figure?


#2

Given power = 1 W
Zener breakdown ${ V}{z }$ = 5V
Minimum voltage ${ V}
{min }$ = 3V
Maximum Voltage ${ V}_{max}$ = 7V