Electrical Engineering Mid - I, September - 2014

1.Which of the following bulbs will have the least resistance ?
  • 220 V, 60 W
  • 220 V, 100 W
  • 115 V, 60 W
  • 115 V, 100 W
Answer: D
2.Kirchhoff's voltage is based on law of conservation of ____
  • charge
  • energy
  • momentum
  • mass
Answer: B
3.In a moving iron meter, the deflecting torque is proportional to
  • Current through the coil
  • Square of the current through the coil
  • Voltage across the coil
  • Square of the Voltage across the coil
Answer: B
4.A sinusoidal current has peak value of 12A. What is its rms value
  • 7. 64 A
  • 24 A
  • 8.48 A
  • 12A
Answer: C
5.In SI system the frequency is expressed in
  • Hz
  • Hz/s
  • cycles
  • cycles-s
Answer: A
6.The power factor of series RLC circuit at resonance is _______
  • 0.8 lagging
  • 0.8 leading
  • unity
  • zero
Answer: C
7.The phase angle between successive phases of a balanced 3-phase system is
  • 900
  • 600
  • 1200
  • 1800
Answer: C
8.In DC generator, which of the following rule is used?
  • Fleming’s right hand rule
  • Fleming’s left hand rule
  • Induction principle
  • none
Answer: A
9.For a DC shunt generator
  • Ia = IL - Ish
  • Ia = IL + Ish
  • IL = Ia - 2Ish
  • Ish = IL + Ia
Answer: B
10.The emf induced in a conductor rotating in a bipolar filed is
  • DC
  • AC
  • Both DC and AC
  • none
Answer: B
11.The limitation of ohm’s law is _______________
Answer: Temperature should be constant
12.Moving coil instruments are used for ___________ measurements.
Answer: DC
13.Three inductors of 5mH, 10 mH and 20 mH are connected in parallel, the equivalent inductance is _____________
Answer: 2.86 mH
14.The direction of force on a current carrying conductor in magnetic field is found by ____________________ rule
Answer: Fleming’s Left hand
15.According to Lenz’s law the electromagnetically induced current always flows in such direction that the action of magnetic field setup by it tends to _________________ the very cause which produces it.
Answer: Oppose
16.In a pure Inductor, the phasor relation between current and voltage is ________
Answer: Current lags voltage by 900
17.An AC voltage is given as v = 10 + 10 sin 314 t. The average and rms values of the voltage are _______________
Answer: 10A, 12.25 A
18.EMF equation of a DC generator is __________
Answer:
19.Magnetization characteristics of DC generator depict the variation of ____________ with filed current at constant speed.
Answer: Generated voltage or no-load voltage
20.The Number of Parallel paths in lap-type winding are _______
Answer: A = P