Electronic Devices and Circuits Mid - I, September - 2010

1.The depletion region in an open circuited p-n junction contains___
  • Electrons
  • Holes
  • uncovered immobile impurity ions
  • Neutralized impurity Atoms
Answer: C
2.Cut in voltage for Ge diode is approximately _______ V
  • 0.2
  • 0.6
  • 1.1 v
  • 1.0
Answer: A
3.The region in which both the collector junctions & emitter junctions are forward biased is _________
  • CB saturation region
  • CB cut off region
  • CB active region
  • CC saturation region
Answer: A
4.Stability factor‘s’ in fixed bias CE amplifier is given by
  • β
  • β+1
  • 1/ β+1
  • 1/ β
Answer: B
5.As the magnitude of the reverse collector junction voltage increases, the effective base width_______
  • Increases
  • decreases
  • remains unaffected
  • zero
Answer: B
6.For ideal rectifier & filter circuits, %regulations must be _____
  • 1%
  • 0.1%
  • 5 %
  • 0%
Answer: D
7.The reverse saturation current in a Pn diode
  • Increase
  • decreases
  • remains constant with increase of bias
  • remains same
Answer: C
8.The reverse saturation current for a Si diode varies ( T is temperature)
  • T^3
  • T^2
  • T
  • T^1.5
Answer: D
9.In full wave rectifier without filter, each diode experiences peak inverse voltage of
  • Vm/√2
  • Vm
  • 2 Vm
  • √2 Vm
Answer: C
10.The equation governing the law of the junction is __________
  • pn(0) = exp(v/vt)n n0
  • np0 = Pno+ni
  • pn(0) = pn0 exp(v/vT - 1)
  • np(0) = pn0 exp(v/vT - 1)
Answer: C
11.The expression for dynamic emitter efficiency is _________
Answer: re^1=dVE/dIE
12.The straight line through the quiescent operating point having slope corresponding to the ac load resistance is _________________
Answer: load line
13.Filter circuit converts _____________ to __________
Answer: unidirectional flow to DC
14.In a half wave rectifier, the lowest ripple frequency is ___________
Answer: Frequency of input sine voltage
15.In a bridge rectifier, peak inverse voltage per diode is _______
Answer: Vm
16.Relation between β1& β is ___________________
Answer: Β1= β +(IcBo+IB) .∂β/∂IB
17.ICEO/ICBO = _______________________________-
Answer: β +1
18.Expression for‘s’ for self bias circuit is _____________
Answer: ∂Ic/∂p or Ic.s/ β(1+ β)
19.Stability factor for fixed bias is _________ if β =40.
Answer: 41
20.Expression for the diffusion capacitance cD in terms of Lp & Dp is _________
Answer: Lp^2/Dp*g