IndiaBIX

Electronics and Communication Engineering - Analog Electronics

Exercise : Analog Electronics - Section 6
1.
A voltage tripler circuit and voltage quadrupler circuit use identical components. Then
voltage regulation in both circuits will be same
voltage regulation in both may or may not be same
voltage regulation in quadrupler circuit will be better than in tripler circuit
voltage regulation in quadrupler circuit will be poorer than in tripler circuit
Answer: Option
Explanation:

Since voltage quadrupler circuit uses more components, voltage drop will be more and voltage regulation poorer.

2.
A Ge diode operated at a junction temperature of 27°C. For a forward current of 10 mA, VD is found to be 0.3 V. If VD = 0.4 V then forward current will be
400 mA
475 mA
477 mA
480 mA
Answer: Option
Explanation:

iD2 = (47.73) x 10 mA = 466 mA.

3.
In a power amplifier the collector current flows for 270° of the input cycle. The operations is
class A
class B
class AB
class C
Answer: Option
Explanation:

In class A operation IC exists for 360°. In class B operation IC exists for 180°. In between there is the class AB.

4.
An amplifier has input impedance of 4 kΩ and output impedance of 80 kΩ. It is used in negative feedback circuit with 10% feedback. If open loop gain is 90, the closed loop input and output impedances are
40 kΩ and 8 kΩ respectively
4 kΩ and 80 kΩ respectively
0.4 kΩ and 800 kΩ respectively
8 kΩ and 160 kΩ respectively
Answer: Option
Explanation:

Closed loop input impedance = 4 (1 + 0.1 x 90) = 40 kΩ,

Closed loop Output impedance = = 8 kΩ.

5.
In figure the current through resistor R
is always equal to 130 mA
may vary between 130 mA and 10 mA
may vary between 65 mA and 10 mA
is always equal to 65 mA
Answer: Option
Explanation:

.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers