Multiple choice

Consider the following statements regarding Photo-transistor: (a) Phototransistor is a light sensitive transistor (b) When the light sensitive surface at the base is exposed to light, the collector-emitter pair of the BJT does not conduct (c) When the light sensitive surface at the base is kept in darkness, a small amount of current flows from the base to the emitter. The small base-emitter current controls the larger collector-emitter current Which of the above statements are false?

  1. Only (a) and (c)

  2. Only (a) and (b)

  3. Only (b) and (c)

  4. All of the above

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement (a) is true. Phototransistor is a light sensitive transistor.Statement (b) is false. When the light sensitive surface at the base is kept in darkness, the collector-emitter pair of the BJT does not conduct.Statement (c) is false. When the light sensitive surface at the base is exposed to light, a small amount of current flows from the base to the emitter. The small base-emitter current controls the larger collector-emitter current.

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