1

### AIPMT 2004

The peak voltage in the output of a half wave diode rectifier fed with a sinusoidal signal without filter is 10 V. The d.c. component of the output voltage is
A
(10/$\sqrt 2$) V
B
$\left( {{{10} \over \pi }} \right)V$
C
10 V
D
(20/$\pi$) V

## Explanation

V = ${{{V_0}} \over \pi }$

$\Rightarrow$ V = $\left( {{{10} \over \pi }} \right)V$
2

### AIPMT 2003

Barrier potential of a p-n junction diode does not depened on
A
diode design
B
temperature
C
forward bias
D
doping density

## Explanation

Barrier potential does not depend in diode design while barrier potential depends upon temperature, doping density and forward biasing.
3

### AIPMT 2003

If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be
A
25 Hz
B
50 Hz
C
70.7 Hz
D
100 Hz

## Explanation

In full wave rectifier the fundamental frequency in ripple is twice of input frequency.
4

### AIPMT 2003

A n-p-n transistor conducts when
A
both collector and emitter are positive with respect to the base
B
collector is positive and emitter is negative with respect to the base
C
collector is positive and emitter is at same potential as the base
D
both collector and emitter are negative with respect to the base

## Explanation

When the collector is positive and emitter is negative with respect to base, it causes the forward biasing for each junction, which causes conduction of current.