120 Important Basic Electrical MCQ Question and Answer | PDF Free Download
1.A nichrome wire used as a heater coil has the resistance of 2 ohm/m. for a heater of 1 Kw at 200 V, the length of wire required will be
- A80 m
- B60 m
- C40 m
- D20 m
2.Which resistor will be physically larger in size?
- A100ohm , 10 W
- B10ohm , 50 W
- C1M ohm , 1/2 W
- D1KOhm , 1 W
3.The condition for the validity under ohm's law is that
- AResistance must be uniform
- BCurrent should be proportional to size of resistance
- CResistance must be wire wound type
- DTemperature at positive end should be more than the temperature at negative end
4.A rheostat differs from potentiometer in the respect that it
- AHas lower wattage rating
- BHas higher wattage rating
- CHas large number of turns
- DOffers large number of tapings
5.The weight of an aluminum conductor as compare to copper conductor of identical cross-section, for the same electrical resistance is
- A50%
- B60%
- C100%
- D150%
6.Voltage dependent resistor are usually made from
- ACharcoal
- BSilicon carbide
- CNichrome
- DGraphite
7.The ratio of mass of proton to that of the electron is nearly
- A1840
- B1804
- C30
- D4
8.The number of electrons in the outer most orbit of carbon atom is
- A3
- B4
- C6
- D7
9.One newton meter is same as
- AOne watt
- BOne joule
- CFive joules
- DOne joule second
10.The flow of current in solids is due to
- AElectrons
- BElectrons and ions
- CAtoms
- DNucleus
11.The resistance of human body is around
- A5 ohms
- B25 ohms
- C250 ohms
- D1000 ohms
12.One commercial unit of energy equals
- A500 watt-seconds
- BOne watt-hour
- COne kilowatt-hour
- DTen kilowatt-hour
13.The electrical energy required to heat a bucket of water to a certain temperature is 4 kWh. If the heat losses are 20 percent, the energy input is
- A2 kWh
- B3.2 kWh
- C5 kWh
- D6 kWh
14.An electrical lamp consumes 100 W of power. If the supply voltage is 220 V the energy consumed in 30 minutes is
- A0.005 kWh
- B0.05 kWh
- C0.5 kWh
- D5 kWh
17.The substances which have a large number of free electrons and offer a low resistance are called
- AInsulator
- BInductors
- CSemi-conductors
- DConductors
18.Out of the following which is not a poor conductor?
- ACast iron
- BCopper
- CCarbon
- DTungsten
19.Out of the following which is an insulating material?
- ACopper
- BGold
- CSilver
- DPaper
20.The property of a conductor due to which it passes current is called
- AResistance
- BReluctance
- CConductance
- DInductance