- Technical Blog From My Notebook

Monday, October 14, 2019

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


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