Question No. 1: Define Amplifier.

Answer: An electronic device for increasing the amplitude of electrical signals, used chiefly in sound reproduction a device consisting of an amplifier combined with a loudspeaker and used to increase the volume of the sound produced by electric guitars and other musical instruments.

 

Question No. 2: What is SCR?

Answer: Thyristors or silicon controlled rectifiers; SCR are found many uses in electronics, and in particular for power control. These devices have even been called the workhorse of high power electronics.Thyristors are able to switch large levels of power are accordingly they used in a wide variety of different applications. Thyristors even finds uses in low power electronics where they are used in many circuits from light dimmers to power supply over voltage protection.

 

Question No. 3: What is ZIGBEE?

Answer: ZIGBEE is a IEEE 802.15.4 based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios.

 

Question No. 4: Define various modes of operation of timer.

Answer: The 555 has three main operating modes, Monostable,Astable, and Bistable. Each mode represents a different type of circuit that has a particular output.

Astable mode, Bistable Mode (or Schmitt Trigger), Monostable mode.

 

Question No. 5: Define signal sampling

Answer: In signal processing, sampling is the reduction of a continuous signal to a discrete signal. A common example is the conversion of a sound wave (a continuous signal) to a sequence of samples (a discrete-time signal).

 


 

 

Network Analysis Lab Viva Questions and Answers

Question No. 6: What is Q factor?

Answer: The Q factor is ratio of inductive reactance to resistance of a coil.

 

Question No. 7: List examples of current sources?

Answer: Semiconductor devices like transistor and diode are treated as current sources.

 

Question No. 8: State Norton’s theorem?

Answer: This theorem states that any linear bilateral network with active network with output terminals AB can be replaced by a single current source in parallel with a single impedance Z.

 

Question No. 9: What is the efficiency during maximum power transfer?

Answer: Efficiency during maximum power transfer 50%.

 

Question No. 10: Define filter?

Answer: A filter is an electrical network that can transmit signals within a specified frequency range.

 

 

Inductive loads :

Loads that produce a magnetic field, often accompanied by heat.

damping :

Decrease in the amplitude of an oscillation or wave motion with time.

Distortion;

In systems that handle electrical signals, distortion is a generally unwanted change in the signal. Not all signal alterations are considered distortion. For instance, a uniform delay or a linear attenuation or amplification would generally not be considered distortion.

gallon (gal):

Imperial gallon. A measure of volume. 1 gal = 4.54596 litre gallon (US) A measure of volume. 1 US gallon = 3.785 litre.

Ohm's law V=IR, current is proportional to the voltage applied.

Electric shock is caused by current and not voltage. 30mA of current is enough to cause ventricular fibrillation in your heart.

Test before Touch. This is a mantra that every electrical engineer should remember. You need to check that there is no voltage before touching any live part. It may have been fed from a different source.

Nowadays, domestic fan regulators do not work on potential divider concept and there is no power loss if you operate the fan at lower/higher speeds.

System earthing and body earthing are different.

All motors are treated in kW/MW, transformers in MVA/kVA and fuses in A.

In electrical cables, size of the core determines the amount of current it can carry and the thickness of Insulation determines the voltage level it can work at.

Zero watt bulbs available in the market are not actually rated for zero watt. Their ratings vary from 5W to 20W.

Types of Relays:
1.Electronic Relay
2.Rectifier Bridge Relay
3.Transistor Relay
4.Hall Effect Relay
5.Gauss Effect Relay
6.Magnetic Amplifying Relay

One of the most common electrical motor used in most applications which is known as induction motor. This motor is also called as asynchronous motor because it runs at a speed less than its synchronous speed.

Synchronous speed is the speed of rotation of the magnetic field in a rotary machine and it depends upon the frequency and number poles of the machine.

Sorry for late guys..

An induction motor always runs at a speed less than synchronous speed because the rotating magnetic field which is produced in the stator will generate flux in the rotor which will make the rotor to rotate, but due to the lagging of flux current in the rotor with flux current in the stator, the rotor will never reach to its rotating magnetic field speed i.e. the synchronous speed.

There are basically two types of induction motor that depend upon the input supply -
1.single phase induction motor and 2.three phase induction motor.

Single phase induction motor is not a self starting motor.

Types Induction Motor;

1.Single Phase Induction Motor
2.Split phase induction motor
3.Capacitor start induction motor
4.Capacitor start capacitor run induction motor
5.Shaded pole induction motor

Three Phase Induction Motor:

1.Squirrel cage induction motor
2.Slip ring induction motor