A blanking pulse is
1.a horizontal positive potential applied to the horizontal deflector plates
2.a high positive potential applied to the vertical deflector plates
3.a high negative potential applied to the control grid
4.a high negative potential applied to the filament
In a colour TV the primary colours used are
1.green yellow violet
2.violet red orange
3.green red blue
4.blue green violet
In a TV receiver the blanking pulses are fed to
1.the horizontal deflector plates
2.the vertical deflector plates
3.the control grid of the electron gun the cathode
4.is coated with barium platino cynide to produce fluorescence
In a TV receiver the picture signals are applied to
1.the vertical deflector plates
2.the horizontal deflector plates
3.the control grid of the electron gun
4.the filament of the electron gun
In a TV the part of electron gun to which blanking pulses are fed is
1.the cathode
2.the grid
3.the anode
4.the filament
In an iconoscope in scanning the image during the blanking period the grid control is supplied with a
1.low negative potential
2.high negative potential
3.high positive potential
4.low positive potential
In television broadcasting video signals are produced using
1.an oscillator
2.a microphone
3.a loud speaker
4.an iconoscope
In television the picture signal frequency is in the order of
1.hertz
2.kilohertz
3.megahertz
4.gigahertz
In TV receiver the synchronizing pulses are fed to
1.The horizontal and vertical deflector plates of the picture tube
2.the control grid
3.the cathode
4.the electron gun
In TV transmission the sound waves are transmitted by
1.phase modulation
2.frequency modulation
3.amplitude modulation
4.amplitude or phase modulation
Interlaced scanning is used in order to
1.increase the brightness of image
2.decrease the brightness of image
3.avoid flickering of image
4.increase the contrast in the image
Scanning is
1.the process in which light audio frequency variations are converted into voltage variations
2.the process in which light intensity is converted into variations in potentials
3.done by a beam of positive rays
4.the process in which audio frequency variations are converted into corresponding video frequency variations
The frame synchronizing pulse is applied to
1.the vertical deflector plates
2.the horizontal deflector plates
3.control grid
4.filament
The frequency of scanning in a television set in frames per second is
1.25
2.50
3.525
4.30
The line synchronizing pulse is applied to
1.the vertical deflector plates
2.the horizontal deflector plates
3.control grid
4.filament
The mosaic in an iconoscope
1.consists of a large number of minute globules of caesium compound on one side of a thick mica sheet
2.is coated with a low work function material such as caesium oxide
3.is coated with zinc sulphide to produce fluorescence
4.is coated with barium platino cynide to produce fluorescence
The photosensitive plate of an Iconoscope is known as
1.mosaic
2.camera
3.grid
4.electron gun
When the image is focused on the mosaic the globules become
1.luminous spot
2.negatively charged
3.positively charged
4.none
When the individual images are transmitted and reproduced at the rate of 25 per sec. human eye records these image as a continuous process. This is due to
1.motion of the picture
2.ability of vision
3.persistence of vision
4.capacity of vision