Electronic Devices and Circuits Mid - I, September - 2011

1.What is the order of doping, from heavily to lightly doped, for each region?
  • base, collector, emitter
  • emitter, collector, base
  • emitter, base, collector
  • collector, emitter, base
Answer: B
2.The voltage where large current starts to flow in a reverse biased p-n junction diode is
  • breakdown voltage
  • barrier potential
  • biasing voltage
  • offset voltage
Answer: A
3.The area at the junction of p-type and n-type materials that has lost its majority carriers is called
  • n- region
  • p- region
  • breakdown region
  • depletion region
Answer: D
4.The peak inverse voltage (PIV) across a non-conducting diode in a bridge rectifier is equal to
  • half the peak secondary voltage
  • twice the peak secondary voltage
  • the peak secondary voltage
  • four time peak secondary voltage
Answer: C
5.The choke filters are not used now a days as they are
  • bulky
  • costlier
  • consume more power
  • all of the above
Answer: D
6.The ripple factor of which filter increase with decrease in load resistance.
  • C – filter
  • LC-filter
  • Inductor filter
  • both b and c
Answer: A
7.What is the ratio of IC to IE?
  • βdc
  • βdc / (βdc + 1)
  • αdc
  • both b and c
Answer: D
8.Which transistor bias circuit arrangement has poor stability
  • collector-feedback bias
  • voltage-divider bias
  • fixed bias
  • emitter bias
Answer: C
9.At saturation, the value of VCE is nearly ________, and IC = ________.
  • zero, zero
  • Vcc, Ic(sat)
  • zero, I(sat)
  • Vcc, zero
Answer: C
10.Changes in  βdc results in changes in
  • Ic
  • Vce
  • the Q-point
  • all of the above
Answer: D
11.The ripple factor of the inductor filter ____________ with decrease in load resistance.
Answer: decreases
12.The Depletion layer capacitance is the capacitance associated with ____________________
p-n junction diode.
Answer: reverse biased
13.The depletion region penetrates more into the _____________________ region.
Answer: lightly doped
14.Zener diode is designed to be operated in the ______________________ condition.
Answer: Reverse Biased
15.The maximum efficiency of a full wave rectifier is ___________________.
Answer: 81.2 %
16.To bias the transistor in saturation region, the emitter-base junction is ___________ biased and
the collector-base junction is _____________ biased.
Answer: forward, forward
17.In common-base configuration of a transistor, when the reverse bias voltage is increased, the
width of the depletion region also increases. This is called _____________________.
Answer: early effect (or) Base Width Modulation
18.____________________ configuration is widely used amongst three transistor configurations.
Answer: Common Emitter
19.Ideally, stability factor should be ____________ to keep operating point stable.
Answer: Zero
20.The excess heat produced at the collector base junction due to self heating may even burn and
destroy the transistor. This is called ______________________ of the transistor.
Answer: Thermal Runaway