WorksheetsDigital Techniques - Electronic Displays
Total questions: 36
Worksheet time: 36mins
An LED which is forward bias produces visible light.
True
False
What is the typical voltage for a LED?
1.6V
3.7V
10.9V
The "flat side"of an LED indicates?
Anode
Cathode
Neutral
What determines the peak wavelength for any LED?
Chemical make up of semiconductor
Current of power supplied to bulb
Frequency supplied to bulb
On a bicoloured LED, how to you produce a third colour?
Varying the voltage
Varying the frequency
Mixing the two primary colours
What does it mean by common cathode and common anode in tricoloured LEDs?
Cathodes are joined, anodes are joined.
All legs are joined together
LEDs are connected in series
LEDs usually indicate?
Power on
Power off
No indication related to power
What type of LED circuit is this?
Common Anode
Common Cathode
Tri-coloured LED circuit
What type of LED circuit is this?
Common Anode
Common Cathode
Tri-Coloured LED
What is this?
Dot matrix LED
Alphanumeric LED
Tri-coloured LED
What is an advantage to dot matrix LED
Cost
Simple to program
Low maintenance
What part of an OLED is selected based on their optical transparency, electrical conductivity and chemical stability?
Anodes
Cathodes
Emissive Layer
How many layers compose an OLED?
4
6
8
What is the top layer of an OLED?
Anode (Seal)
Cathode
Emissive layer
The process of causing light to vibrate in one plane only is called?
Polarisation
Deflection
Thermionic emission
An organic substance that has both crystalline and liquid characteristics at certain temperature range is called?
Liquid crystal
OLED
Reflective LCD
What does liquid crystals tend to align with?
Direction of the field
Area of higher temperature
Magnetic polarity
What display draws less current?
LCD
LED
They pull the same current
What are computer displays lit with?
Fluorescent tubes
A candle being held by an angel
LED flickering
What causes a "bad pixel" on a LCD panel?
Failed transistor
Failed capacitor
Failed resistor
Electrons flowing from a filament across a gap to a metal plate via heat is called?
Edison effect
Faraday's Law
Snell's Law
What is one feature of a cathode ray tube that cannot be duplicated by any other tube or transistor?
Convert electronic signals to visual displays
They don't require any heat transmission
They operate off electron flow
An electron gun, a deflection system and scree are all elements of?
CRT
Heat gun
Ultra Sonic Beacon
What causes a curved path of electrons in a electron gun?
Electrostatic repulsion
Electrostatic deflection
Polarity attraction
The potentiometer used to vary the potential applied to the control grid of a CRT is called?
Brightness controll
Dimmer
Focusing anode
The added positively charged electrode to a CRT called the "focusing anode" is charged with how many volts?
Hundreds
Thousands
Millions
What is the second additional positively charged electrode added to a CTR?
Accelerating Anode
Defocusing Anode
Operation Anode
What is the material called that converts electrons' energy to visible light?
Phosphor
Aquadag
Phosphate
The coating composed of conductive material and has high positive potential on a CTR is called?
Aquadag
Maganese
Helium
Magnetically, electromagnetically and electrostatically are all ways of _________ electron beams.
absorbing
deflecting
attracting
What principle does electrostatic deflection operate off?
Opposites attract
Lenz's law
Edison's law
What is this diagram representing?
Horizontal deflection
Vertical defelction
Sweeping deflection
What can also be used to serve the same purpose of deflection plates?
Coils
Bridges
Magnets
Three dots of different colour grouped together is called?
Tripplets
Triad
Threesome
What is used to see only one colour in a group of three different coloured beams?
Shadow mask
Silk screen
Deflective pads
What is the technique called which scans all the odd and even lines of a reference line perpendicular?
Interlace scanning
Scanning raster
Modulator
