Basic electrical MCQ #15

1) Mobility is the ratio of ______
      (a) Acceleration to velocity
      (b) Drift velocity to applied electric field
      (c) Applied electric field to Drift velocity
      (b) Velocity to acceleration

2) The current is ______ proportional to____, according to the ohm’s law?
      (a) Inversely, power
      (b) Directly, Resistance
      (c) Inversely, potential difference
      (d) Directly, Potential difference

3) Ohm’s law is not applicable for____.
      (a) Semiconductor devices such as diode, transistor, thyristors, SCR
      (b) Magnetic coupled circuit like transformer
      (c) Vacuum tube such as vacuum diode, triode, tetrode, pentode
      (d) All of the above

4) The ohm's law is ______, if the temperature is not constant.
      (a) Not applicable
      (b) Applicable
      (c) Applicable in any condition
      (d) None of the above

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


5) Mass of Neutron is equal to the mass of ___?
      (a) Proton
      (b) Electron
      (c) Nucleus
      (d) Atom

6) The resultant resistance for series combination of R1, R2, and R3 is ______.
      (a) RT = R1 + R2/R3
      (b) RT = R1 + R2 + R3
      (c) 1/RT = 1/R1 + 1/R2 + 1/R3
      (d) RT = 1/R1 + 1/R2 + 1/R3

7) The resultant resistance for parallel combination of R1, R2, and R3 is ______.
      (a) 1/RT = 1/R1 + 1/R2 + 1/R3
      (b) RT = R1 + R2/R3
      (c) RT = R1 + R2 + R3
      (d) RT = 1/R1 + 1/R2 + 1/R3

8) The total resistance of the series combination of resistors is always ______ the individual resistance.
      (a) Less than
      (b) Equal to
      (c) Higher than
      (d) Not defined

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


9) The cut - in voltage for silicon and germanium are 
      (a) 0.3 V, 0.3 V
      (b) 0.3 V, 0.7 V
      (c) 0.7 V, 0.7 V
      (d) 0.7 V, 0.3 V


10) If four bulb B1, B2, B3, and B4 are connected in series. If one of the bulb get damaged, than__.
      (a) Remaining bulbs are glows
      (b) Remaining bulbs are not glows
      (c) Remaining bulbs B2 B3 are glows but B4
      (d) All of the above

11) Two bulbs marked 100W,250V and 200W,250V are connected in series to 250V supply. Power consumed in circuit is equal to
     (a) 100Watt
     (b) 300Watt
     (c) 150 watt
     (d) 67Watt
[Hint: P = V2/R]

12) _____ is not same as Watt.
     (a) Ampere x volt
     (b) (Ampere)2 x ohm
     (c) Ampere/volt
     (d) Joule/sec

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