GATE Electrical Engineering (EE) 2021 Solved Papers

Question : 35 of 65

Marks: +1, -0

In the circuit shown, a

5 {V}

Zener diode is used to regulate the voltage across load

{R}_{0}

. The input is an unregulated

{DC}

voltage with a minimum value of

6 {V}

and a maximum value of

8 {V}

. The value of

{R}_{ {S}}

6 Ω

. The Zener diode has a maximum rated power dissipation of

2.5 {W}

. Assuming the Zener diode to be ideal, the minimum value of

R_{0}

is ___________

Ω .

Solution:

I_{z}

Mininum

=I_{\;\text "Mininum "\;}-I_{L}

Maximum

≥ I_{z k}

{I}_{ {zk}}=

Knee current

I_{z \;\text " Minimum "\;}=\;{V_{i \;\text " Minimum "\;}-V_{z}}/{R_{s}}-\;{V_{z}}/{R_{L} \;\text " Minimum "\;} ≥ 0

=\;{6-5}/{6}-\;{5}/{R_{L \;\text " Minimum "\;}} ≥ 0

=\;{1}/{6} ≥ \;{5}/{R_{L \;\text " Minimum "\;}}

R_{ {L}}

Minimum

≥ 6 × 5=30 Ω

Go to Question:

Prev Question

Next Question