Electrical Basic Questions 5

Electrical Basic Questions 5

1. Conventional flow assumes charges flow from:

A. Positive to negative
B. Positive to positive
C. Negative to positive
D. Negative to negative

ANS : A

2. Electron flow assumes charges flow from:

A. Negative to positive
B. Negative to negative
C. Positive to negative
D. Positive to positive

ANS : A

3. Series resonance occurs when:

A. XL = Xc
B. XL=R
C. Z=R
D. Both A and C

ANS: D

4. The symbol Q refers to:

A. Resonance quotient
B. Quality factor
C. Power quotient
D. Qualification test

ANS :B

5. The ratio of W/VA in an AC circuit means:

A. Power Factor
B. Reactive factor
C. Quality factor
D. Load factor

ANS: A

Electrical Basic Questions 5

6. What is the reciprocal of quality factor?

A. Power factor
B. Dissipation Factor
C. Reactive factor
D. 1 /Q factor

ANS : B

7. In liquids and gases, ionization current results from a flow of:

A. Positive or negative ions
B. Free Electrons
C. Ions that are lighter in weight than electrons:
D. Protons

ANS : B

8. VL = Vc in a series RLC circuit when:

A. The value of the impedance is minimum
B. The power factor is zero
C. The current leads the total voltage by 90°
D. The total voltage is zero

ANS : A

9. At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 µF?

A. 7.12 KHz
B. 7.12 Hz
C. 7.12MHz
D. 7.12 GHz

ANS: A

10. Property of an electric circuit that dissipates electric energy:

A. Reactance
B. Impedance
C. Resistance
D. Conductance

ANS : C

Electrical Basic Questions 5

11. What is the other name of relative permittivity?

A. Dielectric strength
B. Potential gradient
C. Breakdown voltage
D. Specific inductance capacity

ANS : D

12. In a series RLC circuit

A. The current lags VL by 90°
B. The current leads VL by 90°
C. XL leads X. by 90°
D. Z = jXL at resonance

ANS : A

13.Resistor with colored bands in the body

A. Wire-wound resistor
B. Carbon-composition resistor
C. Potentiometer
D. Rheostat

ANS : B

14. In a resonant circuit, if Q > 10 resonant frequency______ bandwidth.

A. Bisects
B. Exceeds
C. Is less than
D. Is equal to

Ans : B

15. Which of the following conditions is not true for a series RLC circuit at resonance?

A. Z=j XL
B. XL = Xc
C. The power factor is one.

ANS : A

Electrical Basic Questions 5

16. The current is ————- times the maximum current at half-power points of a resonance curve.

A. 0.707
B. 1.414
C. 0.5
D. 0.632

ANS : A

17. A gang capacitor is a variable capacitor in which capacitance is varied by changing the:

A. Dielectric
B. Number of plates
C. Distance between plates
D. Plate Area

ANS  : D

18. In an ac circuit with inductive reactance, the

A. Phase angle of the circuit is always 45°
B. Voltage across the inductance must be 90° out-of-phase with the applied voltage

C. Current through the inductance lags its induced voltage by 90°
D. Current through the inductance and voltage across it are l80° out-of-phase

ANS : C

19. If three 9 mH inductors are connected in parallel without mutual inductance then the total inductance is

A. 3 mH
B. 9 mH
C. 27 mH
D. 18 mH

ANS : A

20. What is the specific resistance of a pure germanium?

A. 55 Ohm-cm
B. 55 Ohm-m
C. 55 Ohm-mm
D. 55 KOhm-m

ANS : A

Electrical Basic Questions 5

21. Two capacitors of capacitance 9 µF and 18 µF in series will have a total capacitance of:

A. 27 µF
B. 6 pF
C. 162 µF
D. 180 µF

ANS : B

22. In a series RLC circuit:

A. Increasing the frequency decreases the resistance
B. Both XL and Xc change as frequency changes
C. Increasing the frequency increases the resistance
D. Impedance will always decrease

ANS : B

23. A series RLC circuit has a ________ power factor at its half-power points

A. Unity
B. Leading
C. Lagging
D. Either B or C

ANS: D

24.Kirchhoff’s laws (KCL and KVL) are applicable to:

A. DC circuits
B. AC circuits
C. Passive networks alone
D. DC as well AC circuits

ANS 😀

25.A tank circuit is a:

A. Parallel LC Circuit
B. Series LC circuit
C. A resonant circuit
D. A non-resonant circuit

ANS : A

Electrical Basic Questions 5

26. A capacitive load always has a______ power factor.

A. Leading
B.Lagging
C. Zero
D. Unity

ANS : A

27. What is the temperature coefficient of the resistance Eureka?

A. Infinity
B. Negative
C. Almost Zero
D. Positive

ANS : C

28. As applied to a series RLC circuit, bandwidth means

A.The frequency range for maximum power transfer
B. The difference between the highest and lowest frequencies of the oscillator
C. The frequency at which XL = Xc
D. The separation of the half-power points

ANS : D

29. Which is considered as the effect of a dielectric material?

A.Increasing capacitance
B. Decreasing capacitance
C. Reducing the working voltage
D. Increasing the distance between the plates

ANS : A

30. The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfer, the load voltage will be:

A. 60 V
B. 15 V
C. 30V
D. 20 V

ANS : C

Electrical Basic Questions 5

31. If a capacitor is rated for 200V dc, what is its effective ac working voltage?

A. 50 V
B. 100 V
C. 200 V
D. 400 V

ANS : C

32. If resonant frequency is 10 kHz and quality factor is 50, then

A. Bandwidth is 200 Hz
B. XL = is 50,000 Ohm
C. R is 50 Ohm
D. XC = is 50,000 Ohm

ANS : A

33.Which statement is true?
A. A series resonant circuit is of high impedance
B. A parallel resonant circuit is of low impedance
C. A series resonant circuit is inductive if it operates at a frequency higher than resonant frequency
D.A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency

ANS : C

34. What is considered as the most important value of a sine wave?

A. Effective value
B. Peak value
C. Average value
D. Instantaneous value

ANS : A

35. An AC series circuit is composed of a resistance of 20 ohm, inductive reactance of 40 ohm, and a capacitive reactance of 15 ohm. If a current of 1 ampere is flowing, what is the applied voltage?

A.320 V
B. 32 V
C. 220 V
D. 22 V

ANS : B

Electrical Basic Questions 5

36. An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil

A. Faradic current
B. Transient ac current
C. Inductive current
D. Capacitive current

ANS : A

37. The value of temperature coefficient (alfa) is dependent upon

A. The nature of material and temperature
B. The length of material
C. The cross-sectional area of the material
D. The volume of the material

38. At what frequency will the current in a series RLC circuit reach its maximum value for an applied voltage of 15 V with R = 500 ohm , L = 100 µH and C = 0.001 µF?

A. 403 kHz
B. 503 KHz
C. 603 kHz
D. 303 kHz

ANS : B

39. If two equal resistances connected in series across a certain supply are no connected in parallel across the same supply, the power produced will be __________ that of series connection:

A. One-half
B. Four times
C. One-fourth
D. Two times

ANS : B

40. The voltage lags the current by Pi/2 cycle in a:

A.Purely resistive circuit
B. Purely inductive circuit
C. Purely capacitive circuit
D. Circuit containing resistance, capacitance and inductance