Telecommunication Objective Questions with answers, UVH,VHF,LED,LCD

Telecommunication Objective Questions with answers, UVH,VHF,LED,LCD

TELECOMMUNICATION

Wireless radio communication was developed by

Ans : Guglielmo Marconi

First telecommunication device was

Ans : Telegraph

The frequencies transmitted by TV station is called

Ans : Channel

For radio transmission BBC uses

Ans : Short waves

Short waves ranging  from 14m to 60m are used for

Ans : International communication

The waves which travel long distances without loss in intensity

Ans : Short waves (14m to 60m)

Short waves ranging from 14m to 60m are used for

Ans : International communication

The waves which travel long distance without loss in intensity

Ans : Short waves (14m to 60m)

VERY HIGH FREQUENCY (VHF)

Electro magnetic spectrum between 30MHz and 300 MHz is called

Ans:VHF

VHF is used in

Ans:Radio Transmission and Radar

ULTRA HIGH FREQUENCY (UHF) 

Frequency ranging from 300 MHZ to 3GHz is called

Ans : UHF

UHF is used in 

Ans : Ratio Transmission and Radar

ULTRA HIGH FREQUENCY

Frequency ranging from 300MHZ to 3GHz is called

Ans : UHF

UHF is used in

Ans : T.V, Communication of satellite etc.

Telex

Ans : Teleprinter Exchange

The device used for communicating the text and images through telephone lines

Ans : Fax machine

The device used to convert audio frequency signals into sound

Ans : Loudspeaker

The instrument which has ability to convert sound into magnetic energy

Ans : Tape recorder

LCD AND LED

LCD - Liquid Crystal Display  

LED - Light Emitting Diode

LED is used as monitor, clocks, watches, calculators, telephones etc.

LED was invented by

Ans : Oleg Losev and Nick Holonyak

Working principle of LED 

Ans : Electroluminescence