Electronic Circuit Analysis Mid - I, February - 2011

1.The voltage gain of well designed single stage CB amplifier is essentially determined by ac collector load and 
  • Emitter resistor Re
  • ac alpha
  • Input resistance emitter diode
  • ac beta
Answer: C
2.The bandwidth of an amplifier can be increased by
  • decreasing the capacitance of its bypass capacitors
  • minimizing the stray capacitance
  • increasing the input signal frequency
  • Cascading it
Answer: B
3.For the operation of enhancement only N- Channel MOSFET , value of gate voltage has to be
  • High positive
  • high negative
  • low positive
  • zero
Answer: A
4.The most desirable feature of transformer coupling is its
  • Higher voltage gain
  • wide frequency range
  • ability to provide impedance matching
  • ability to eliminate hum from the output
Answer: C
5.Lower cutoff frequency of an amplifier is primarily determined by the
  • Internal capacitance of the active device
  • Stray capacitance between its wiring and ground
  • ac beta(β) value of its active devices
  • Capacitances of coupling and bypass capacitor
Answer: D
6.Class D amplifier uses what type of transistors
  • JFETs
  • BJTs
  • MOSFETs
  • can use any
Answer: C
7.The main reason for the variation of amplifier gain with frequency is
  • the presence of capacitance internal and external
  • due to interstage transformation
  • the logarithmic increase in its output power
  • miller effect
Answer: A
8.The emitter of a CE amplifier has no AC voltage because of the
  • DC voltage unit
  • Bypass Capacitor
  • Coupling capacitor
  • load resistance
Answer: C
9.For matching a circuit of output impedance 200Ω with a load of 8 Ω the turn ratio of the two winding transformer should be
  • 25
  • 1/25
  • 1/5
  • 5
Answer: D
10.Typical value of hie is
  • 1k
  • 25k
  • 50k
  • 100k
Answer: A
11.The alpha (α) cut off frequency of a transistor is _________ than is beta (β) cut-off frequency.
Answer: HIGHER
12.The parameter h22 has units of _______.
Answer: SEIMENS
13.The alpha (α) of the transistor ___________ with the increase in frequency.
Answer: DECREASES
14.In depletion mode and N- Channel DE MOSFET conducts with Vgs is _______.
Answer: ZERO
15.A CC Amplifier has highest __________ but lowest ________.
Answer: CURRENT GAIN AND POWER GAIN
16.Direct coupled amplifiers are especially suited for amplifying extremely ______ frequency signals.
Answer: LOW
17.The current gain of single stage CE amplifier is nearly equal to __________.
Answer: Beta (β)
18.The DC resistance of transformer coupling is _________so it is more efficient.
Answer: Low
19.A MOSFET can be easily destroyed by any _________ on its gate.
Answer: Stray voltage
20.The positive gate operation of a N- Channel Depletion MOSFET is known as ______.
Answer: Enhancement mode