Semiconductor Electronics Part 2

The circuit diagram used to study the characteristic curve of a zener diode is connected to variable power supply ( 0−15V) as shown in figure. A zener diode with maximum potential VZ=10V and maximum power dissipation of 0.4W is connected across a potential divider arrangement. The value of resistance RP connected in series with the zener diode to protect it from the damage is ______Ω.