HELP15

Question

Answer 1

QUESTION 4

4.1)

4.1.5)

UJT is a transistor with two PN junctions.

The above statement is false, because the uni-junction transistor essentially consists of a lightly-doped N-type silicon bar with a small piece of heavily doped P-type material alloyed to its one side to produce single P-N junction.

The single P-N junction accounts for the terminology unijunction.

Answer 2

4.1.4)

In an N-channel JFET the majority carriers are electrons.

The above statement is true, because depending upon the majority carriers,  JFET has been classified into two types,

(1) N-channel JFET with electrons as the majority carriers.

(2) P-channel JFET with holes as the majority carriers.

Answer 3

3.4)

Circiut is fullwave rectifier with capacitive filter.

Frequency is  Hz.

Load current is mA.

Capacitor value .

Maximum secondary voltage is 10 V.

3.4.1)

The output DC voltage :

The output DC voltage for full wave rectifier is defined as .

From the given data V.

Substitute in .

Thus, DC output voltage is 6.366 V.

Solution:

DC output voltage is 6.366 V.

Answer 4

4.1.3)

MOSFETs are widely uded in digital applications.

The above statement is true, because the MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic signals in the electronic devices.

The MOSFET is a three terminal device such as source, gate, and drain.

The MOSFET is the most common transistor and can be used in both analog and digital circuit.

Answer 5

4.1.2)

In the FET the output current controls the input voltage.

The above statement is true, because FET is a voltage controlled device, i.e, current at the output controls the voltage at the input terminal.

Answer 6

3.4.2)

Circiut is fullwave rectifier with capacitive filter.

Frequency is  Hz.

Load current is mA.

Capacitor value .

Maximum secondary voltage is 10 V.

The output ripple voltage :

The output ripple voltage for full wave rectifier is defined as .

Where Load resistance.

.

Substitute V and A in above expression.

Substitute , , Hz and V in .

V.

The output ripple voltage is 1.333 V.

Solution:

The output ripple voltage is 1.333 V.

Answer 7

4.1.1)

The common emitter amplifier produces 0º phase shift on the output.

The above statement is false, because when input voltage is increased, then, Ib is increased and Ic is also increased. Since Rc is between Vcc and Collector, the voltage drop across Rc is increased.

Thus, collector-to-ground voltage is decreased.

In a similar fashion, when input voltage is decreased, collector-to-ground voltage is increased.

Thus, it produces a 180º phase shift.(input positive, output negative and vice versa).

Answer 8

(4.2)

A negative feedback amplifier is an electronic amplifier that subtracts a fraction of its output from its input, so that negative feedback opposes the original signal.

The applied negative feedback improves performance (gain stability, linearity, frequency response) and reduces sensitivity to parameter variations due to manufacturing or environment.

The use of negative feedback does several things:

It flattens and extends the frequency response.

It reduces distortion generated in the stages encompassed by the feedback loop.

It reduces the effective output impedance of the amplifier, which increases the damping factor.