Basic electrical MCQ #6

1) Conductance: mho: ____________?

      (A) resistance: ohm

      (B) capacitance: henry

      (C) inductance: farad

      (D) lumen: steradian

2) With three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals_____________?

      (A) 10 W

      (B) 20 W

      (C) 40 W

      (D) 60 W

3)The number of electrons in the outer most orbit of carbon atom is___________?

      (A) 3

      (B) 4

      (C) 6

      (D) 7

4) Voltage dependent resistors are used ____?

      (A) for inductive circuits

      (B) to suppress surges

      (C) as heating elements

      (D) as current stabilizers

5) If the efficiency of a machine is to be high, what should be low __________?

      (A) Input power

      (B) Losses

      (C) True component of power

      (D) kWh consumed

ANSWER: | 1-a | 2-d | 3-b | 4-b | 5-b |

6) Electric current passing through the circuit produces_____________?

      (A) magnetic effect

      (B) luminous effect

      (C) thermal effect

      (D) chemical effect

7) Voltage dependent resistors are usually made from________________?

      (A) charcoal

      (B) silicon carbide

      (C) nichrome

      (D) graphite

8) An open resistor, when checked with an ohm-meter reads_____________?

      (A) zero

      (B) infinite

      (C) high but within tolerance

      (D) low but not zero

9) Ohm’s law is not applicable to__________?

      (A) semi-conductors

      (B) DC circuits

      (C) small resistors

      (D) high currents

10) Which method can be used for absolute measurement of resistances ____________?

      (A) Lorentz method

      (B) Releigh method

      (C) Ohm’s law method

      (D) Wheatstone bridge method

ANSWER: | 6-c | 7-c | 8-b | 9-a | 10-d |

11) Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes__________?

      (A) 1/9 times

      (B) 3 times

      (C) 9 times

      (D) unchanged

12) Bulbs in street lighting are all connected 

in_____________?

      (A) parallel

      (B) series

      (C) series-parallel

      (D) end-to-end

13) In the case of direct current_________?

      (A) magnitude and direction of current remains constant

      (B) magnitude of current remains constant

      (C) magnitude of current changes with time

      (D) magnitude and direction of current changes with time 

14) Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct?

      (A) 100 W lamp will glow brighter

      (B) 40 W lamp will glow brighter

      (C) Both lamps will glow equally bright

      (D) 40 W lamp will fuse

15) An electric filament bulb can be worked from____________?

      (A) DC supply only

      (B) AC supply only

      (C) Battery supply only

      (D) All above

ANSWER: | 11-c | 12-a | 13-a | 14-b | 15-d |