Load resistance
RL = 2 kΩ = 2 × 103 Ω
Potential difference at the end points of load resistance
V = 15V
∴ Current in RL
IL = \(\frac{V}{R_{L}}=\frac{15}{2 \times 10^{3}}\) = 7.5 × 10-3 Amp.
∴ IL = 7.5 mA
The lowest working current of zener diode
(Iz) = 10 mA
Current in circuit
I = IL + IZ
= 7.5 mA + 10 mA = 17.5 mA
Zener diode and load resistance (RL) are connected in parallel so potential difference between the current ends of zener diode = Potential at the ends points of RL = 15 V