HELP14

Question

Answer 1

Question (1)

Step 1:

Draw a circuit diagram using above specifications.

Apply Kirchoff Voltage law to the first loop.

Apply Kirchoff voltage law to the second loop.

Substitute in the equation .

Hence the current passing through the load resistor is 0.7059 A.

Step 2:

Find voltage drop across the load resistor.

Voltage across the load resistor is .

Hence voltage across the load resistor is 5.6472 v.

Solution :

Voltage across the load resistor is 5.6472 v.

Answer 2

(2.1)

Step 1:

The resistance of the circuit is .

The inductance of the circuit is 0.1 H.

The capacitance of the circiut is .

The resonance frequency of a circuit is .

Resonant frequency is 35.588 Hz.

Solution :

Resonant frequency is 35.588 Hz.

Answer 3

(2.2)

Step 1 :

Find the impedance of the circuit.

Assume input frequency as 60 Hz.

Impedance due to resistor element is .

Impedance due to inductor element is

Impedance due to capacitive element is

First Resistance and inductor is in series, hence .

The equilvalent series impedance is parallel to the capacitance, .

Total impedance of the circuit is .

Solution :

Total impedance of the circuit is .

Answer 4

(2.3)

Step 1:

Find the total current.

Applied voltage is 200 v.

Total impedance of the circuit is .      (From 2.2)

Total current in the circuit is .

Total current in the circuit is .

Solution :

Total current in the circuit is .

Answer 5

(2.4)

Draw the phasor diagram.

Total current in the circuit is .     (From 2.3)

can be written in polar form as .

Phasor diagram :

Plot the phasor diagram .

Answer 6

3.1.1

Uses of the PN junction diode :
It is used as rectifier in DC Power Supplies.
It is used in Demodulation or Detector Circuits.
It is used in clamping networks as DC Restorers.
It is used in clipping circuits for waveform generation.
It is used as switches in digital logic circuits.

Answer 7

3.1.2.

Uses of the Zener diode :
It is used to limit voltages, preventing surges from damaging electronics circuits.
It is used as voltage regulator.
It is used as over voltage protector, as voltage reference.

Answer 8

3.1.3

Uses of the Varactor diode :

(1) It is used in RF design.

(2) They can be found in voltage controlled oscillators such as in a phase locked loop and are

      used in almost all radio, cellular and wireless receivers.

(3) It is used in RF filters for tuning purposes, parametric amplifiers,

     parametric oscillators and frequency synthesizers.

Answer 9

3.2

Advantages of an LC filter :

(1) It is less dependent on the load current.

(2) DC voltage drop across L is much smaller because its DC resistance R is very small.

(3) In choke input filter, current flows continuously. Therefore the transformer is used more

     efficiently.

(4) Ripple content at the output is low.

Answer 10

3.3

Voltage Regulation :

Voltage regulation is found on nearly every distribution circuit.

It is important to maintain a consistent voltage so that lighting, appliances, motors, and the power system itself work as efficiently as possible.

Zener diode regulates the voltage in electric circuit, so it is used as voltage regulator.

SEL voltage regulation products monitor and control voltage regulators and allow for advanced capabilities such as remote engineering access, built-in logic, and advanced control based on voltage profile, time-of-day, or other dynamic events.