Q.1
Zener diode are used as voltage regulator
  • true
  • false
Q.2
Is the element added to the type p semiconductors.
  • Antimony
  • Boron
  • Chlorine
  • Argon
Q.3
A diode made of GaAs emits dark ....... light
  • red
  • green
  • blue
Q.4
Optocouplers are available in Integrated circuit form
  • true
  • false
Q.5
A photodiode is used in ................... mode
  • Reverse Bias
  • reverse biased
  • reverse biaseding
  • All of above
Q.6
The reference level of a signal can be changed by using ........
  • Clipper circuit
  • clamper circuit
  • zero level circuit
  • rectifier circuit
Q.7
In solar cell the short circuit current .......with light intensity
  • increases
  • decreases
  • remains unchanged
  • falls down to zero
Q.8
A device that converts the energy of light directly into electrical energy is
  • photodiode
  • LED
  • Solar Cell
  • rectifier diode
Q.9
An optocoupler is used as
  • isolator circuit
  • coupling device
  • magnifying device
  • colourful device
Q.10
Colour of the LED output light is decided by
  • coloured glass covering it
  • colour added at time of manufacturing
  • material used for its construction
  • size of LED
Q.11
Semiconductor are substances whose electrical conductivity lies between that of
  • conductor and insulator
  • conductor and metal
  • plastic and wood
  • insulator and gold
Q.12
A diode is used as rectifier to convert
  • dc to ac
  • ac to dc
  • low current into high current
  • high current into low current
Q.13
When the diode is operated in forward bias mode
  • it offers high resistance
  • it becomes non conductive
  • it is open switch
  • it offers very low resistance
Q.14
A pn junction diode which has a sharp breakdown voltage is known as
  • zener diode
  • rectifier diode switching diode
  • switching diode
  • varactor diode
Q.15
Zener diodes are mostly used in
  • current regulator circuit
  • power regulator circuit
  • voltage regulator circuit
  • rectifier circuit
Q.16
Current limiting resistance value used in series with LED is normally between
  • 220Ω to 330Ω
  • 220kΩ to 330kΩ
  • 220MΩ to 330MΩ
  • 50Ω to 55Ω
Q.17
The silver ring marked on diode indicates
  • anode
  • tolerance ± %
  • current rating
  • cathode
Q.18
What does the diode do?
  • Making a uni directional current flow.
  • Making a bi directional current flow.
Q.19
What we have inside of a charger?
  • Transformer
  • Diode
  • none of them
  • both of them
Q.20
Why do we need a transformer in the charger?
  • Boosting up the voltage
  • Lowering down the voltage
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