Basic Electrical MCQ #17

1) If the frequency of the supply is increase, then reactance of inductive circuit is ______.  
      (a) decrease
      (b) increase
      (c) remain same
      (d) inductive reactance does not depend on supply frequency

2) What is the value of reactance of a 2µF capacitor of 2.5 kHz?
      (a) 15.91 Ω
      (b) 159.1 Ω
      (c) 1591 Ω
      (d) 1.591 Ω

3) When the load connected to ac is purely resistive, the reactive part is ______.
      (a) equal to resistive part
      (b) infinite
      (c) not defined
      (d) zero 

4) In a purely capacitive circuit current _____voltage by _____
      (a) lags, 90
      (b) in phase
      (c) leads, 90
      (d) out of phase

ANSWER: | 1-b | 2-c | 3-d | 4-c |

5) Capacitive reactance is measured in____.
      (a) Henry
      (b) Farad
      (c) Weber
      (d) Ohms 

6) A pure capacitor has its leakage resistance equal to___.       
      (a) infinite value
      (b) finite value
      (c) capacitance
      (d) unity

7) Arrange following alloys in decreasing order of their resistivity.       
      (a) Constantan- German silver- Monel metal
      (b) German silver- Constantan- Monel metal
      (c) Constantan- Monel metal- German silver
      (d) German silver- Monel metal- Constantan 

8) Which of the following has highest dielectric strength?
      (a) Marble
      (b) Polystyrene
      (c) cotton
      (d) Transformer oil

ANSWER: | 5-d | 6-a | 7-a | 8-b |

9) The capacitance per unit volume is maximum for
      (a) mica capacitor
      (b) ceramic capacitor
      (c) air capacitor
      (d) electrolytic capacitor 

10) Which of the following is/are not used as earth continuity conductors?
      (a) gas pipe
      (b) structural steel
      (c) oil pipe
      (d) All of the above

11) ____ type of wiring is mostly safe from fire and mechanical injury.
      (a) casing capping
      (b) CTS /TRS
      (c) conduit
      (d) cleat 

12) The minimum height of lamp fitting from the ground level should be____.
      (a) 5 m
      (b) 1.5 m
      (c) 10 m
      (d) 1 m

ANSWER: | 9-d | 10-d | 11-b | 12-b |