Electronics MCQs for MDCAT Practice

Physics section, Electronics chapter. Sample questions from past PMC papers.

1. Question 1
   If an AC voltage of 100V peak value is applied as input to a half wave rectifier and then a full wave rectifier, the rms values of outputs will be respectively:
   • A.35V and 35V
   • B.35V and 70V
   • C.50V and 70V
   • D.70V and 140V
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2. Question 2
   In a p-n junction, there is no appreciable current if
   • A.p-section is made positive and n-section negative
   • B.a potential difference is applied across the junction making p-section negative and n-section positive
   • C.a potential difference is applied across the junction
   • D.it is impossible
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3. Question 3
   The anode of a diode is 0.2 volts positive with respect to its cathode. Is it forward biased?
   • A.Yes, because any positive voltage at the anode causes forward bias.
   • B.Yes, because the anode is at a higher potential than the cathode.
   • C.No, because the anode must be negative relative to the cathode for forward bias.
   • D.No, because the voltage is too low to overcome the barrier potential.
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4. Question 4
   In which of the following, output is similar to NAND gate if input A=0 and input B = 1.
   • A.NOR.
   • B.XNOR.
   • C.XOR.
   • D.Both B and C.
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5. Question 5
   In n-p-n transistor, p works as
   • A.Collector
   • B.Emitter
   • C.Base
   • D.Any of these
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6. Question 6
   In the breakdown region zener behaves like a
   • A.Constant current
   • B.Constant voltage
   • C.Constant resistance
   • D.None of them
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7. Question 7
   Which of the following is not correct regarding Zener diodes?
   • A.It is used as a half-wave rectifier
   • B.It is used as a shunt regulator
   • C.It is used as an AC voltage stabilizer
   • D.Both B and C
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8. Question 8
   The electrical conductivity of an intrinsic semiconductor at room temperature is low mainly because:
   • A.It has a large forbidden energy gap
   • B.It contains no charge carriers
   • C.It has a very few charge carriers
   • D.Its atoms do not vibrate
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