First slide

Diodes

Question

In the following circuit, three P-N junction diodes $D_{1}, D_{2}$ and $D_{3}$ are ideal for the following potential of A and B. The correct increasing order of resistance between A and B will be
Sno. A B
(i) -10V -5V
(ii) -5V -10V
(iii) -4V -12V

Moderate

A

i< ii < iii
B

iii < ii <i
C

ii = iii <i
D

i = iii <i

Solution

$(i) V_{A} = - 10 V a n d V_{B} = - 5 V D i o d e s D 1 a n d D 3 a r e r e v e r s e b i a s e d a n d D 2 i s f o r w a r d b i a s e d .$
$\Rightarrow R_{A B} = R + \frac{R}{4} + \frac{R}{4} = \frac{3 R}{2}$
$(i i) W h e n V_{A} = - 5 V a n d V_{B} = - 10 V D i o d e s D 2 i s r e v e r s e d b i a s e d a n d D 1 a n d D 3 a r e f o r w a r d s b i a s e d .$
$\Rightarrow R_{A B} = \frac{R}{4} + \frac{R}{2} + \frac{R}{4} = R$
$(i i i) I n t h i s c a s e a l s o, D i o d e s D 2 i s r e v e r s e d b i a s e d a n d D 1 a n d D 3 a r e f o r w a r d s b i a s e d . \Rightarrow e q u i v a l e n t r e s i s \tan c e b e t w e e n A a n d B i s a l s o R .$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App