# Basic Electrical Engineering 5

First Year Engineering Common to all Branches: Basic Electrical Engineering 5

Subject: Basic Electrical Engineering 5

Part 5: List for questions and answers of Basic Electrical Engineering

Q1. In case of Short Circuit,_______Current will flow in the Circuit.
a) Zero
b) Very Low
c) Normal
d) Infinite

Q2. (Ohm) is the Unit of ___________?
a) Resistance (R)
b) Inductive Reactance ( XL)
c) Capacitive Reactance (Xc)
d) All of the above

Q3. In a three-phase system, the voltages are separated by
a) 45°
b) 90°
c) 120°
d) 180°

Q4. In a three-phase system, when the loads are perfectly balanced, the neutral current is
a) zero
b) one-third of maximum
c) two-thirds of maximum
d) at maximum

Q5. In a Y-connected circuit, the magnitude of each line current is
a) one-third the phase current
b) three times the corresponding phase current
c) equal to the corresponding phase current
d) zero

Q6. A constant load power means a uniform conversion of
a) mechanical to electrical energy
b) electrical to mechanical energy
c) current to voltage
d) voltage to current

Q7. Polyphase generators produce simultaneous multiple sinusoidal voltages that are separated by
a) certain constant phase angles
b) certain constant frequencies
c) certain constant voltages
d) certain constant currents

Q8. In a Y-connected circuit, between each line voltage and the nearest phase voltage, there is a phase angle of
a) 0°
b) 30°
c) 60°
d) 120°

Q9. The most common type of ac motor is the
a) single-phase induction motor
b) two-phase induction motor
c) three-phase induction motor
d) two-phase squirrel-cage motor

Q10. In a Y-connected source feeding a -connected load,
a) each phase of the load has one-third of the full line voltage across it
b) each phase of the load has two-thirds of the full line voltage across it
c) each phase of the load has the full line voltage across it
d) each phase of the load has a voltage across it equal to

Q11. A sine wave voltage is applied across an inductor. When the frequency of the voltage is decreased, the current
a) is increased
b) is decreased
c) does not change
d) momentarily goes to zero

Q12. An ohmmeter is connected across an inductor and the pointer indicates zero ohms. The inductor is
a) good
b) open
c) shorted
d) partly shorted

Q13. The winding resistance of a coil can be increased by
a) increasing the number of turns
b) using a thinner wire
c) changing the core material
d) increasing the number of turns or using thinner wire

Q14. When the current through an inductor decreases, the amount of energy stored in the electromagnetic field
a) increases
b) decreases
c) remains the same
d) doubles

Q15. Three 15 mH inductors are in series. The total inductance is
a) 15 mH
b) 30 mH
c) 45 mH
d) 5 mH

Q16. The inductance of an iron-core coil decreases if
a) the number of turns is decreased
b) the iron core is removed
c) the length of the coil decreases
d) none of the above

Q17. When the current through an inductor is cut in half, the amount of energy stored in the electromagnetic field
a) is quartered
c) doubles
d) does not change

Q18. The voltages in Problem 5 are measured at a certain frequency. To make the resistor voltage less than the inductor voltage, the frequency is
a) increased
b) decreased
c) doubled
d) not a factor

Q19. To increase the current in a series RL circuit, the frequency
a) should be increased
b) should be decreased
c) should be constant
d) cannot be determined without values

Q20. When the frequency is decreased, the impedance of a parallel RL circuit
a) increases
b) decreases
c) remains constant
d) is not a factor

Part 5: List for questions and answers of Basic Electrical Engineering