Semiconductor Electronics Part 2

Consider the figure with current in the directions shown below. Voltage across Rs,Vs=22−15=7V
Current through Rs,I=‌

Vs

RS

⇒‌‌I=‌

7

35

=‌

1

5

A
Current through 90Ω resistance,
I1=‌

Vz

RL

=‌

15

90

=‌

1

6

A
∴ Current through Zener diode, I2=‌

1

5

−‌

1

6

=‌

1

30

A
∴ Power through Zener diode,
P=V2I2
=15×‌

1

30

=‌

1

2

=0.5W=5×10−1W
Comparing with the given value in question i.e., x×10−1, the value of x=5.