A `10 V` Zener diode along with a seriers resistance R is connected across a `40V` supply. Calculate the minimum value of the resistance, ar required, if the maximum Zener current is `50mA`.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Understand the Circuit
We have a Zener diode connected in parallel with a load resistance (RL) and a series resistance (R). The total supply voltage (V_supply) is 40V, the Zener voltage (V_Z) is 10V, and the maximum Zener current (I_Z(max)) is 50mA.

### Step 2: Apply Kirchhoff’s Voltage Law
According to Kirchhoff's Voltage Law, the voltage across the series resistance (R) plus the Zener voltage (V_Z) should equal the supply voltage (V_supply). Therefore, we can write the equation:
\[ V_{supply} = I \cdot R + V_Z \]
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