Basic Electrical Engineering Mid - I, September - 2014

1.If five 0.05pF capacitors are connected in parallel. The equivalent capacitance is
  • 0.01 pf
  • 0.25 pf
  • 0.5pf
  • 0.025pf
Answer: B
2.If a delta-connected network consists of R ohms in each leg of delta, what is its equivalent in star?
  • R ohms
  • R/3 ohms
  • 3R ohms
  • 2R ohms
Answer: B
3.Thevenin's equivalent circuit consists of
  • Series combination of Rth, Isc
  • Parallel combination of Rth, Vth
  • Series combination of Rth, Vth
  • Parallel combination of Rth, Rl
Answer: C
4.The form factor of a sine wave is ______
  • Max. value / RMS value
  • Average value / RMS value
  • RMS value / Max. value
  • RMS value / Average value
Answer: D
5.The r.m.s value of a sinusoidal current is ______
Answer: A
6.In a pure capacitor, the voltage _____________
  • is in phase with the current
  • is out of phase with the current
  • lags behind the current by 900
  • leads the current by 900
Answer: C
7.When the frequency of applied voltage in a series RL circuit increases, what happens to the inductive reactance?
  • Decreases
  • Remains the same
  • Increases
  • Becomes zero
Answer: C
8.The primary and secondary of a transformer are _______ coupled
  • Electrically
  • magnetically
  • electrically and magnetically
  • mechanically
Answer: B
9.An ideal transformer is one which _____________
  • has some losses and leakage reactance
  • has no losses and leakage reactance
  • has same number of primary and secondary turns
  • none
Answer: B
10.Transformer operates on the principle of ______________
  • Self-inductance
  • Mutual-inductance
  • Both A and B
  • none
Answer: B
11.Inductor stores energy in the form of __________ field.
Answer: Magnetic
12.An ideal current source has _____________ resistance.
Answer: Infinite
13.For maximum power transfer from source to load, internal resistance of source should be equal to _______ resistance.
Answer: Load
14.The value of crest factor for sinusoidal wave is ___________
Answer: 1.414
15.The frequency of the AC supply used in India is _________ cycles / second.
Answer: 50
16.Apparent power is expressed in _________
Answer: Volt-ampere
17.In a series RL circuit R = 50 ohms and XL = 75 ohms, what is the impedance _____________
Answer: 90.14 ohms
18.Transformer core is laminated in order to reduce _________
Answer: Eddy current losses
19.The open-circuit test on a transformer is always made on ________ winding.
Answer: Low-voltage
20.Short–circuit test on transformer gives _______ losses.
Answer: Full load copper losses