MCQOPTIONS
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MCQOPTIONS
This section includes 122 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
_ For testing appliances, the wattage of test lamp should be$? |
| A. | Very low |
| B. | Low |
| C. | High |
| D. | Any value |
| Answer» D. Any value | |
| 52. |
_ A resistance having rating 10 ohms, 10 W is likely to be a$? |
| A. | Metallic resistor |
| B. | Carbon resistor |
| C. | Wire wound resistor |
| D. | Variable resistor |
| Answer» D. Variable resistor | |
| 53. |
_ A closed switch has a resistance of$? |
| A. | Zero |
| B. | About 50 ohms |
| C. | About 500 ohms |
| D. | Infinity |
| Answer» B. About 50 ohms | |
| 54. |
_ A nichrome wire used as a heater coil has the resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be$? |
| A. | 80 m |
| B. | 60 m |
| C. | 40 m |
| D. | 20 m |
| Answer» B. 60 m | |
| 55. |
_ Insulating materials have the function of$? |
| A. | Preventing a short circuit between conducting wires |
| B. | Preventing an open circuit between the voltage source and the load |
| C. | Conducting very large currents |
| D. | Storing very high currents |
| Answer» C. Conducting very large currents | |
| 56. |
_ Three resistances of 10 ohms, 15 ohms and 30 ohms are connected in parallel.The total resistance of the combination is$? |
| A. | 5 ohms |
| B. | 10 ohms |
| C. | 15 ohms |
| D. | 55 ohms |
| Answer» B. 10 ohms | |
| 57. |
_ Which of the following can have negative temperature coefficient?$? |
| A. | Compounds of silver |
| B. | Liquid metals |
| C. | Metallic alloys |
| D. | Electrolytes |
| Answer» E. | |
| 58. |
_ If I, R and t are the current, resistance and time respectively, then according to Joule’s law heat produced will be proportional to$? |
| A. | I²Rt |
| B. | I²Rt² |
| C. | I²R²t |
| D. | I²R²t² |
| Answer» B. I¬¨‚â§Rt¬¨‚⧠| |
| 59. |
_ In an electric kettle water boils in 10 m minutes. It is required to boil the boiler in 15 minutes, using same supply mains$? |
| A. | Length of heating element should be decreased |
| B. | Length of heating element should be increased |
| C. | Length of heating element has no effect on heating if water |
| D. | None of the above |
| Answer» B. Length of heating element should be increased | |
| 60. |
_ Current velocity through a copper conductor is$? |
| A. | the same as propagation velocity of electric energy |
| B. | independent of current strength |
| C. | of the order of a few ^.s/m |
| D. | nearly 3 x 108 m/s |
| Answer» D. nearly 3 x 108 m/s | |
| 61. |
_Electric current passing through the circuit produces$? |
| A. | Magnetic effect |
| B. | Luminous effect |
| C. | Thermal effect |
| D. | Chemical effect |
| Answer» D. Chemical effect | |
| 62. |
_Out of the following which is not a poor conductor?$? |
| A. | Cast iron |
| B. | Copper |
| C. | Carbon |
| D. | Tungsten |
| Answer» C. Carbon | |
| 63. |
_The weight of an aluminium conductor as compared to a copper conductor of identical cross-section, for the same electrical resistance, is$? |
| A. | 50 % |
| B. | 60 % |
| C. | 100 % |
| D. | 150 % |
| Answer» B. 60 % | |
| 64. |
_A 3 Q resistor having 2 A current will dissipate the power of$? |
| A. | 2 watts |
| B. | 4 watts |
| C. | 6 watts |
| D. | 8 watts |
| Answer» D. 8 watts | |
| 65. |
_With rise in temperature the resistance of pure metals$? |
| A. | Increases |
| B. | Decreases |
| C. | First increases and then decreases |
| D. | Remains constant |
| Answer» B. Decreases | |
| 66. |
_Which of the following quantities remain the same in all parts of a series circuit?$? |
| A. | Voltage |
| B. | Current |
| C. | Power |
| D. | Resistance |
| Answer» C. Power | |
| 67. |
_Two resistors are said to be connected in series when$? |
| A. | Same current passes in turn through both |
| B. | Both carry the same value of current |
| C. | Total current equals the sum of branch currents |
| D. | Sum of IR drops equals the applied e.m.f. |
| Answer» B. Both carry the same value of current | |
| 68. |
_Which of the following material has nearly zero temperature coefficient of resistance?$? |
| A. | Manganin |
| B. | Porcelain |
| C. | Carbon |
| D. | Copper |
| Answer» B. Porcelain | |
| 69. |
_Which is the best conductor of electricity?$? |
| A. | Iron |
| B. | Silver |
| C. | Copper |
| D. | Carbon |
| Answer» C. Copper | |
| 70. |
_The S.I. unit of power is$? |
| A. | Henry |
| B. | Coulomb |
| C. | Watt |
| D. | Watt-hour |
| Answer» D. Watt-hour | |
| 71. |
_An electric filament bulb can be worked from$? |
| A. | D.C. supply only |
| B. | A.C. supply only |
| C. | Battery supply only |
| D. | All above |
| Answer» E. | |
| 72. |
_Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as$? |
| A. | 4 : 25 |
| B. | 25 : 4 |
| C. | 2 : 5 |
| D. | 5 : 2 |
| Answer» D. 5 : 2 | |
| 73. |
_The resistance of a conductor varies inversely as$? |
| A. | Length |
| B. | Area of cross-section |
| C. | Temperature |
| D. | Resistivity |
| Answer» C. Temperature | |
| 74. |
_Two resistances Rl and Ri are connected in series across the voltage source where Rl > Ri. The largest drop will be across$? |
| A. | Rl |
| B. | Ri |
| C. | Either Rl or Ri |
| D. | None of them |
| Answer» B. Ri | |
| 75. |
_Out of the following which is an insulating material?$? |
| A. | Copper |
| B. | Gold |
| C. | Silver |
| D. | Paper |
| Answer» E. | |
| 76. |
_A glass rod when rubbed with silk cloth is charged because$? |
| A. | It takes in proton |
| B. | Its atoms are removed |
| C. | It gives away electrons |
| D. | It gives away positive charge |
| Answer» D. It gives away positive charge | |
| 77. |
_The ratio of mass of proton to that of electron is nearly$? |
| A. | 1840 |
| B. | 1480 |
| C. | 30 |
| D. | 4 |
| Answer» B. 1480 | |
| 78. |
_The condition for the validity under Ohm's law is that$? |
| A. | Resistance must be uniform |
| B. | Current should be proportional to the size of the resistance |
| C. | Resistance must be wire wound type |
| D. | Temperature at positive end should be more than the temperature at negative end |
| Answer» B. Current should be proportional to the size of the resistance | |
| 79. |
_The number of electrons in the outer most orbit of carbon atom is$? |
| A. | 3 |
| B. | 4 |
| C. | 6 |
| D. | 7 |
| Answer» C. 6 | |
| 80. |
Conductance is reciprocal of$? |
| A. | Resistance |
| B. | Inductance |
| C. | Reluctance |
| D. | Capacitance |
| Answer» B. Inductance | |
| 81. |
The minimum charge on an ion is$? |
| A. | Equal to the atomic number of the atom |
| B. | Equal to the charge of an electron |
| C. | Equal to the charge of the number of electrons in an atom (#) zero |
| D. | None of these |
| Answer» C. Equal to the charge of the number of electrons in an atom (#) zero | |
| 82. |
Sparking occurs when a load is switched off because the circuit has high |
| A. | Resistance |
| B. | Inductance |
| C. | Capacitance |
| D. | Impedance |
| Answer» C. Capacitance | |
| 83. |
The insulation on a current carrying conductor is provided |
| A. | To prevent leakage of current |
| B. | To prevent shock |
| C. | Both of above factors |
| D. | None of above factors |
| Answer» D. None of above factors | |
| 84. |
The resistance of a copper wire 200 m long is 21 ω. If its thickness (diameter) is 0.44 mm, its specific resistance is around$ |
| A. | 1.2 x 10-8 ω-m |
| B. | 1.4 x 10-8 ω-m |
| C. | 1.6 x 10-8 ω-m |
| D. | 1.8 x 10-8 ω-m |
| Answer» D. 1.8 x 10-8 ≈ì√¢-m | |
| 85. |
In a lamp load when more than one lamp are switched on the total resistance of the load |
| A. | Increases |
| B. | Decreases |
| C. | Remains same |
| D. | None of the above |
| Answer» C. Remains same | |
| 86. |
Voltage dependent resistors are used |
| A. | For inductive circuits |
| B. | To suppress surges |
| C. | As heating elements |
| D. | As current stabilizers |
| Answer» C. As heating elements | |
| 87. |
When current flows through heater coil it glows but supply wiring does not glow because |
| A. | Current through supply line flows at slower speed |
| B. | Supply wiring is covered with insulation layer |
| C. | Resistance of heater coil is more than the supply wires |
| D. | Supply wires are made of superior material |
| Answer» D. Supply wires are made of superior material | |
| 88. |
When one leg of parallel circuit is opened out the total current will |
| A. | Reduce |
| B. | Increase |
| C. | Decrease |
| D. | Become zero |
| Answer» D. Become zero | |
| 89. |
Which of the following materials has a negative temperature coefficient of resistance? |
| A. | Copper |
| B. | Aluminum |
| C. | Carbon |
| D. | Brass |
| Answer» D. Brass | |
| 90. |
What will be energy used by the battery if the battery has to drive 6.28 x 10¹⁸ electrons with potential difference of 20 V across the terminal ?$ |
| A. | 5 joules |
| B. | 10 joules |
| C. | 15 joules |
| D. | 20 joules |
| Answer» E. | |
| 91. |
Resistance of 220 V, 100 W lamp will be |
| A. | 4.84 Q |
| B. | 48.4 Q |
| C. | 484 ft |
| D. | 4840 Q |
| Answer» D. 4840 Q | |
| 92. |
Bulbs in street lighting are all connected in |
| A. | Parallel |
| B. | Series |
| C. | Series-parallel |
| D. | End-to-end |
| Answer» B. Series | |
| 93. |
Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open |
| A. | There will be heavy current in the main line |
| B. | Rest of the two bulbs will not light |
| C. | All three bulbs will light |
| D. | The other two bulbs will light |
| Answer» E. | |
| 94. |
In a series circuit with unequal resistances |
| A. | The highest resistance has the most of the current through it |
| B. | The lowest resistance has the highest voltage drop |
| C. | The lowest resistance has the highest current |
| D. | The highest resistance has the highest voltage drop |
| Answer» E. | |
| 95. |
It becomes more difficult to remove |
| A. | Any electron from the orbit |
| B. | First electron from the orbit |
| C. | Second electron from the orbit |
| D. | Third electron from the orbit |
| Answer» E. | |
| 96. |
If a parallel circuit is opened in the main line, the current |
| A. | Increases in the branch of the lowest resistance |
| B. | Increases in each branch |
| C. | Is zero in all branches |
| D. | Is zero in the highest resistive branch |
| Answer» D. Is zero in the highest resistive branch | |
| 97. |
The four bulbs of 40 W each are connected in series swift a battery across them, which of the following statement is true? |
| A. | The current through each bulb in same |
| B. | The voltage across each bulb is not same |
| C. | The power dissipation in each bulb is not same |
| D. | None of the above |
| Answer» B. The voltage across each bulb is not same | |
| 98. |
The substances which have a large number of free electrons and offer a low resistance are called |
| A. | Insulators |
| B. | Inductors |
| C. | Semiconductors |
| D. | Conductors |
| Answer» E. | |
| 99. |
The condition for the validity under Ohm’s law is that$ |
| A. | resistance must be uniform |
| B. | current should be proportional to the size of the resistance |
| C. | resistance must be wire wound type |
| D. | temperature at positive end should be more than the temperature at negative end |
| Answer» B. current should be proportional to the size of the resistance | |
| 100. |
When electric current passes through a metallic conductor, its temperature rises. This is due to |
| A. | Collisions between conduction electrons and atoms |
| B. | The release of conduction electrons from parent atoms |
| C. | Mutual collisions between metal atoms |
| D. | Mutual collisions between conducting electrons |
| Answer» B. The release of conduction electrons from parent atoms | |