WorksheetsBasic Electrical & Electronics-03/06/2021
Total questions: 15
Worksheet time: 8mins
Liquid crystal represents which one of the following state:
Crystalline solid-state
Amorphous solid state
Liquid state
Liquid crystal state
By which properties, the orientation of molecules in a layer of liquid crystals can be changed?
Magnetic field
Electric field
Electromagnetic field
Gallois field
Liquid Crystals possess the properties of
Solids
Liquids
Both solids and liquids
LED works only in ______ bias
Forward
Reverse
The colour of emitted light from LED depends on
physical dimensions of LED
Number of available carriers
Type of semiconductor material used
Number of recombinations taking place
The advantage of LED is
Low cost
Long Life
Small in Size
All the above
When forward biased, LED emits light because of
Recombination of electrons with holes
Light generated in breaking the covalent bonds
Light produced by collisions
None of the above
A Temperature Sensor Measures:
The Light (UV)
The Pressure (Weight)
The Temperature (Hot/Cold)
Motion (Movement)
Automatic doors would use a:
Motion Sensor
Light Sensor
Temperature Sensor
Moisture Sensors
What type of sensor would be used in this kettle?
Light Sensor
Temperature Sensor
Infra-red sensor
Pressure Sensor
What is a tamper?
A door/window shows open when it's actually closed
The panel can't communicate with the sensor
The cover of the sensor has been removed or misaligned
A low battery
What is a tamper?
A door/window shows open when it's actually closed
The panel can't communicate with the sensor
The cover of the sensor has been removed or misaligned
A low battery
The numbers on the digital clocks are made of with....
a liquid crystal display.
plasma flat panel.
black-white pixels
cartoon images.
What is in the picture?
Capacitor
Resistor
Diode
Inductor
What is in the picture?
Fuse
Switch
Integrated Circuit
Light Emitting Diodes (LED)
