Electrical and Electronics Engineering Mid - I, September - 2014

1.The principle of dynamically induced EMF is utilized in
  • Transformer
  • Choke
  • Generator
  • Thermocouple
Answer: C
2.The scale used with a moving coil meter is
  • linear
  • non-linear
  • square law scale
  • none of these
Answer: A
3.A lap wound DC machine has 400 conductors and 8 poles. The voltage Induced per conductor is 2 V. The machine generates a voltage of
  • 100 V
  • 200 V
  • 400 V
  • 800 V
Answer: A
4.The series field of a short shunt DC generator is excited by ____________ Current.
  • Armature
  • Shunt Field
  • Load
  • IL + ISH
Answer: C
5.The direction of rotation of a DC shunt motor can be reversed by interchanging
  • The supply terminals
  • The field terminals only
  • The armature terminals only
  • The field or armature terminals
Answer: D
6.Kirchoff’s second law is based on law of conservation of
  • charge
  • energy
  • momentum
  • mass
Answer: A
7.Resistivity of a wire depends on
  • Length
  • Material
  • cross sectional area
  • none of these
Answer: B
8.The main purpose of performing open circuit test on a transformer is to measure its
  • Copper Loss
  • Core Loss
  • Total Loss
  • Insulation distance
Answer: B
9.Transformer will operate at maximum efficiency when
  • Hysteresis Loss = Eddy Current Loss
  • Eddy Current Loss = Copper Loss
  • Copper Loss = Iron Loss
  • Hysteresis Loss =Copper Loss
Answer: C
10.The PMMC meter can measure
  • Only ac quantities
  • Only dc quantities
  • both ac and dc quantities
  • None of these
Answer: B
11.The function of a starter in a DC Motor is to limit the ______________ to a safer value.
Answer: Starting Current
12.The emf induced in the armature conductors of a dc motor is ______________________.
Answer: back or counteremf or alternating emf
13.The speed of a dc series motor at no load will be ________________________________.
Answer: Infinite
14.The deflecting torque of a moving iron instrument is _______________.
Answer: I2(dL/dθ)/2
15.The emf induced in a dc generator is ________________ induced emf.
Answer: Dynamically
16.The short circuit test in a transformer is used to determine the __________________ loss at full load.
Answer: Copper
17.A transformer should never be connected to a _____________ source.
Answer: Dc
18.An electric heater draws 10A from a 120V line. The resistance of the heater is _____________.
Answer: 12 ohms
19.Swamping resistance is usually made of ___________________.
Answer: Manganin
20.When n resistances each of value r are connected in parallel, then resultant resistance is X. When these n resistances are connected in series, total resistance is _______________.
Answer: N2X