Basic Electrical Engineering Mid - I, September - 2011

1.Form Factor is the ratio of
  • RMS Value/Peak Value
  • Mean value/Peak value
  • RMS value/Mean Value
  • Mean Value/RMS Value
Answer: C
2.A60Hz power line voltage of 120V is applied across a resistance of 10 ohms. The RMS value of current
  • 168A
  • 8.48A
  • 16.8A
  • 12A
Answer: D
3.OHM is the unit of following except
  • Resistance
  • Capacitance
  • Capacitive reactance
  • Inductive reactance
Answer: B
4.If RA = RB= RC = R in star network, RAB= RBC =RCA = in it’s equivalent delta network.
  • R/3
  • 3R
  • R
  • 2R/3
Answer: B
5.A Transformer will have low efficiency at ________________Load
  • Full load
  • Half load
  • No-load
  • None
Answer: C
6.The relationship between Electrical energy( E),Voltage( V) and Charge( Q) is
  • E=Q / V
  • E=QV^2
  • E=Q x V
  • E= V / Q^2
Answer: C
7.The internal resistance of an ideal voltage source is
  • zero
  • infinity
  • a finite value
  • none of the above
Answer: A
8.The maximum power transfer theorem can be applied
  • Only to DC circuits
  • Only to AC circuits
  • To both DC &AC circuits
  • neither of the two
Answer: C
9.In purely inductive circuit
  • reactive power is zero
  • apparent power is zero
  • actual power is zero
  • none
Answer: C
10.which of the following waves has the highest value of form factor
  • triangular wave
  • sine wave
  • square wave
  • rectangular wave
Answer: D
11.In a Transformer Core is laminated to reduce____________________
Answer: Eddy current loss
12.In R-L circuit current __________________ the Voltage.
Answer: Lags
13.Condition for maximum efficiency of Transformer is___________________
Answer: Iron loss=copper loss
14.The voltage and current relation of an Inductor__________________________
Answer: vs=Ldi/dt
15.In Thevenins equivalent circuit resistance is in________________________with thevenins voltage source
Answer: series
16.Capacitance is the property of a circuit element to ____________
Answer: Store electric charge
17.The best conductor of electricity is __________________
Answer: Silver
18.In series combination C equivalent =___________________
Answer: C1C2 / C1+C2
19.The time period of a sinusoidal with 200Hz frequency will be__________________________
Answer: 0.005 s
20.Current magnification occurs in___________________________
Answer: parallel resonant circuit