Interview Questions.

Q1. Explain Why Modulation Is Required?

When we need to transmit electric signal over an antenna, through unfastened area, it must be transformed into electro-magnetic waves. Only electro-magnetic waves have the belongings to tour via space (vacuum) at the speed of light message sign or voice alerts have low frequencies.

Signal with low frequencies cannot tour longer distance.

To make msg sign or voice sign tour longer distance.

To boom the signal to noise ratio.

Q2. What Is Modulation And Give Methods Used For Modulation?

Modulation is the method by which a few traits of signal referred to as “Carrier Signal” is various in accordance to the instant cost of the some other signal known as “Message Signal”.

Methods of Modulations are:

Angle Modulation

Amplitude Modulation

Q3. Give The Limitation Of Pll Synthesizer?

It suffers from tolerance which passed off in its analog components. Here, quick term drifts are induced due to variation inside the filter out and VCO components.

Q4. What Is Multiplexing. Explain Its Types?

 Multiplexing is described as the system wherein some of message signals are combined together to shape composite signals in order that they can be transmitted through the commonplace channel.

Types of multiplexing:

Frequency Division Multiplexing

Time Division Multiplexing

Q5. What Is The Difference Between Analog Modulation And Digital Modulation?

In analog modulation bandwidth required is low while in virtual modulation due to better bit fee, better channel bandwidth are required.

Q6. What Are Different Types Of Communication System?

Their are 3 basic forms of communication system, which are-

1) Simplex Communication System:

Here, the verbal exchange system this is able to transmitting statistics through, called simplex transmission system.  In simplex type, one unit is geared up with a transmitter and the alternative facet is geared up with best one receiver however conversation is done handiest one manner by way of transmitter.

For Example: T.V. Broadcast gadget.

2) Half-Duplex Communication System: 

Here, the conversation gadget that is capable of transmitting facts in each directions but the go with the flow is best one manner at a given time that why it is known as half of-duplex. In HDX kind, one unit is prepared with transmitter as well receiver at one end and a transmitter-receiver at the other quit however statistics can’t drift simultaneously in each the guidelines.

For  Example: Walkie-Talkie”

three) Full Duplex Communication System:

Here the glide of communique takes area in each the path concurrently. Full-duplex Ethernet connections paintings on the principles of complete-duplex where data packets are obtained and despatched concurrently at a given time.

For Example: Phone

Q7. What Do You Understand By Communication?

Communication is the method via which information is both transferred or received from one area to every other via verbal exchange channel.

Q8. Explain Different Modes Used For Communication?

According to the mode of communique, it is divided into

1) Line Communication: In this mode of communication, the medium of transmission is a couple of conductors called transmission strains. Both the Tx and Rx are related via  a twine or line.

2) Wireless or Radio Communication: In this mode, a message is transmitted via a open medium as in area by way of electromagnetic wave that are known as radio waves.

Q9. Explain The Term Companding?

Companding is the time period derived from the combination of two phrases

COMPANDING= COMPRESSION + EXPANDING

In the technique of Companding, the susceptible signals are amplified and strong alerts are attenuated before making use of them to a uniform quantizer.