Basic Electrical Engineering Mid - I, September - 2010

1.Ohm’s law is applicable to _________
  • Semiconductors
  • Electrolytes
  • Arc Lamps
  • None
Answer: D
2.The maximum efficiency of power transfer to the load is _____ %
  • 25
  • 50
  • 75
  • 100
Answer: B
3.An alternating current is given by i=200 Sin(314t π/3)amps. The maximum value & frequency of the current are __________
  • 200A, 50Hz
  • 100√2A, 50Hz
  • 200A,100Hz
  • 200A,25Hz
Answer: A
4.A Y arrangement of resistances has each resistance of 3Ω. The equivalent delta arrangement will have each resistance of values ______________ Ω.
  • 9
  • 6
  • 3
  • 1
Answer: A
5.The length of a phasor in a phasor diagram normally represents the __ values of the alternating quantity.
  • Effective
  • Average
  • Peak
  • None
Answer: A
6.The capacitance of a parallel plate capacitor is not affected by _______
  • Area of Plates
  • Thickness of plates
  • Separation between plates
  • Nature of Dielectric.
Answer: B
7.While determining RTH in thevinins and Nortons equivalent _________
  • Only current sources are made dead
  • Only voltage Voltage sources are made dead
  • All independent sources are made dead.
  • All current & voltage sources are made dead.
Answer: B
8.Kirchoffs laws are valid for __________ circuits.
  • Linear
  • Passive time invariant
  • Non Linear
  • both Linear & Non Linear
Answer: D
9.The standard supply frequency in India is ____________ Hz.
  • 25
  • 50
  • 60
  • 100
Answer: B
10.A Circuit having neither any energy source nor emf source is called the _______ circuit.
  • Unilateral
  • Bilateral
  • Passive
  • Active
Answer: C
11.The capacitive reactance of a circuit __________ with the increase if frequency.
Answer: Decreases
12.If rated Dc voltage is applied instead of AC to the primary of a transformer then _________ of the transformer will burn.
Answer: Primary
13.A Sinusoidal voltage varies from Zero to maximum of 250V. The voltage at the instant of 60o of the full cycle will be ____________
Answer: 216.5A
14.If Pi be the iron losses and Pc be the copper losses on full load, then the condition for obtaining the maximum efficiency at 3/4th full load is ___________
Answer: Pc=(16/9)Pi
15.A transformer can have Zero regulation at ___________ power factor.
Answer: Leading
16.The chemical used in breather is ________.
Answer: SILICA GEL
17.The power consumed in an AC circuit will be minimum when the phase difference between current & applied voltage is _______o.
Answer: 90
18.The symbol ‘j’ represents _____ rotation of the phasor _____ degrees.
Answer: COUNTER CLOCKWISE, 90
19.An alternating current is represented as i=70.7Sin (520t π/6). The frequency & RMS value of the current are __________Hz, _______A.
Answer: 82.7,50
20.The no load current in a transformer lags the applied voltage by _____
Answer: 75