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Basic Concepts (MCQs With Explanatory Answers)

Basic Concepts (Electrical Fundamentals) MCQs With Explanatory Answers

1.  What is The Basic Three Electrical Quantities. 

  1. Resistance, Capacitance, Inductance
  2. Power, Voltage, Conductance
  3. Voltage, Current, Resistance(Impedance)
  4. Current , Reluctance, Inductance

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Answer:    3.    Voltage, Current, Resistance (Impedance)

Explanation: The reader may select option 1, but do not forget that there is no concept of Option 1 ( Resistance, Capacitance , inductance ) without Option 3 ( Voltage, Current, Power ) Hence The  basic Electrical Quantities are Voltage, Current and Power ( Option 3).

2.   In case of Short Circuit,_______Current will flow in the Circuit. 

  1. Zero.
  2. Very Low
  3. Normal.
  4. Infinite

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Answer:      4.    Infinite

Explanation: At the short circuited point, the voltage difference is very low (about Zero) So then put the value in → I = P/V …. so if we put V = 0, Then Current will be infinite.

 3.  Ω (Ohm) is the Unit of ___________?

  1. Resistance (R)
  2. Inductive Reactance ( XL)
  3. Capacitive Reactance (Xc)
  4. All of the above
  5. None of the above

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Answer:     4.   All of the above

Explanation: As we better know that Inductive and Capacitive reactances are resistances, so the unit of all these quantities should be same i.e Ohm (Ω)

4.   Siemens or Mho () is the unit of ____________?

  1. Conductance
  2. Admittance
  3. Both 1 & 2
  4. None of the above

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Answer:      3.        Both 1 & 2.

Explanation: Conductance (G) is the inverse/reciprocal of Resistance (R) and the SI unit of Conductance (G) is Siemens (S) or Mho (℧) and Admittance (Y) is the inverse/reciprocal of Impedance(Z). but we also know that impedance(Z) is resistance in AC Circuits. So both of (R) and (Z) are Resistances. Therefore the reciprocal/inverse of R and Z  = G and Y respectively. And G and Y are same. So the SI unit of these Quantities ( G and Y ) = Siemens (S) or (or Mho (℧).

5.  What quantity of charge must be delivered by a battery with a Potential Difference of 110 V to do 660J of Work?

  1. 0.6 C
  2. 6 C
  3. 60 C
  4. 600 C

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Answer:     2.    6C

Explanation:  Q = W / V = 660J / 110V = 6C

6.  The quantity of a charge that will be transferred by a current flow of 10 A over 1 hour period is_________ ?

  1. 10 C
  2. 3.6 x 104 C
  3. 2.4 x 103 C
  4. 1.6 x 102 C

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Answer:     2.        3.6 x 104 C

Explanation: Q = I x t = 10A x ( 60 x 60 Sec) = 3.6 x 104 C

 7.  If a 100Watts Bulbs ON for 10 hours, then what will be the amount of consumed Electricity? 

  1. 100Watts
  2. 100Watts per Hour
  3. 1000 Watts ( 1kW)
  4. 1kWh = 1 Unit of electricity

Show Explanatory Answer

Answer:     4.    1kWh = 1 Unit of Electricity.

Explanation: The Basic Unit for Consumed Electricity is kWh = one unit (also Called Board of Trade Unit =BTU). Now, 10 hours x 100 Watts = 1kWh. (1kW = 1000Watts.

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    1. its all about BTU i.e british thermal units BTU: energy required to raise the temp of room by a degree 1 ton=12000 BTU/hr

    2. because initially people use ice to decrease the temperature and ice required in tons that’s why 1 ton ac cooling power equal to 1 ton of ice cooling power

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  2. The Basic Unit for Consumed Electricity is kWh = one unit (also Called Board of Trade Unit =BTU).
    Now, 10 hours x 100 Hours = 1kWh. Watts = 1000Watts.

    how to get 100 hours???

    1. Hi Amit… Just Click on “Expand Explanatory Answer”.
      le me know if you want to know more. Thanks

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