GATE Electronics and Communications (EC) 2019 Solved Paper

Question : 47 of 65

Marks: +1, -0

In the circuit shown, the breakdown voltage and the maximum current of the Zener diode are

20 {V}

and

60 {mA}

, respectively. The values of

{R}_{1}

and

{R}_{ {L}}

are

200 Ω

and

1 {k} Ω

, respectively. What is the range of

{V}_{ {i}}

that will maintain the Zener diode in the 'on' state?

Solution:

{l}_{\z \max}=60 {mA}

{L}_{ {L}}=\;{20}/{1000}=20 {mA}

l_{\z \min}

not given,

{l}_{ {zmin}}=0 {mA}

Now

l_{s}=l_{z}+ l_{L}

∴ l_{smin}=l_{\z \min }+ l_{L}

=0+20 {mA}

∴ l_{smin}=20 {mA}

Now

l_{S}=\;{V_{S}-V_{Z}}/{200}

∴ 20 {mA}=\;{ {V}_{ {S}}-20}/{200}

∴ V_{ {s}}=24 {V}

Now

l_{smax}=|_{zmax}+ {I}_{ {L}}

=60+20

l_{smax}=80 {mA}

∴ l_{S}=\;{V_{S}-V_{Z}}/{200}

∴ 80 {mA}=\;{ {V}_{ {S}}-20}/{200}

∴ V_{ {s}}=36 {V}

Go to Question:

Prev Question

Next Question