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 Which of the following statements is true?
  • a)
    Solid state switches are applications for an AC output
  • b)
    LED’s can be driven by transistor logics
  • c)
    Only NPN transistor can be used as a switch
  • d)
    Transistor operates as a switch only in active region
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
Which of the following statements is true?a)Solid state switches are a...
Output devices like LED’s only require a few milliamps at logic level DC voltages and can therefore be driven directly by the output of a logic gate. However, high power devices such as motors or lamps require more power than that supplied by an ordinary logic gate so transistor switches are used.
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Which of the following statements is true?a)Solid state switches are a...
Explanation of Correct Answer: Option B
LEDs, or Light Emitting Diodes, are semiconductor devices that emit light when an electric current flows through them. They can indeed be driven by transistor logic, making option B the correct statement.

Why Option B is True:
- Transistor as a Switch: Transistors can function as electronic switches. When used in this capacity, they can control the flow of current to an LED.
- Logic Levels: Transistor logic levels (HIGH and LOW) can effectively turn the LED on and off, allowing for precise control in circuits.
- Drive Capability: Transistors can handle different current levels, which means they can drive LEDs directly or through resistors, depending on the application.

Why Other Options are Incorrect:
- Option A: Solid-state switches can be used for both AC and DC outputs, not limited to AC only.
- Option C: Both NPN and PNP transistors can be used as switches. NPN transistors are commonly used for sinking current, while PNP transistors are used for sourcing current.
- Option D: Transistors operate as switches primarily in the saturation and cutoff regions, not just the active region. In saturation, they act as closed switches, and in cutoff, they act as open switches.

Conclusion:
Understanding these concepts is crucial for effective circuit design, particularly when integrating LEDs and transistors in electronic applications.
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Which of the following statements is true?a)Solid state switches are applications for an AC outputb)LED’s can be driven by transistor logicsc)Only NPN transistor can be used as a switchd)Transistor operates as a switch only in active regionCorrect answer is option 'B'. Can you explain this answer?
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