120 Important Basic Electrical MCQ Question and Answer | PDF Free Download

1.The draft velocity of the electron is

• AVery small as compared to speed of light
• BEqual to speed of light
• CAlmost equal to speed of light
• DGreater than speed of light
Correct Answer : (A)

Very small as compared to speed of light

Explanation:

2.In gases, the flow of current is due to

• AElectrons only
• BPositive ions only
• CElectrons and positive ions
• DElectrons, positive ions, negative ions
Correct Answer : (D)

Electrons, positive ions, negative ions

Explanation:

3.Two resistor are said to be connected in series when

• ASame current passes in turn through both
• B Both carry the same value of current
• CTotal current equals to the sum of branch current
• D Sum of IR drops equals to the applied e.m.f
Correct Answer : (A)

Same current passes in turn through both

Explanation:

4.A resistance having rating 10 ohms, 10 W is likely to be a

• AMetallic resistor
• BCarbon resistor
• CWire wound resistor
• DVariable resistor
Correct Answer : (D)

Variable resistor

Explanation:

5.The minimum charge on an ion is

• AEqual to the atomic number of an atom
• BEqual to the charge of an electron
• CEqual to the charge of number of electron in an atom
• DZero
Correct Answer : (B)

Equal to the charge of an electron

Explanation:

6.A 3 ohm resistor having 2A current will dissipate the power of

• A2 watts
• B4 watts
• C6 watts
• D8 watts
Correct Answer : (C)

6 watts

Explanation:

7.Which of the following statement is true?

• AA galvanometer with low resistance in parallel is a voltmeter
• BA galvanometer with high resistance in parallel is a voltmeter
• CA galvanometer with low resistance in series is an ammeter
• DA galvanometer with high resistance in series is an ammeter
Correct Answer : (C)

A galvanometer with low resistance in series is an ammeter

Explanation:

8.The resistance of a few meters of wire conductor in closed electrical circuit is

• APractically zero
• BLow
• CHigh
• DVery High
Correct Answer : (A)

Practically zero

Explanation:

9.A 500 W, 220 V bulb is supplied with 110V. power consumption by the bulb will be

• ASlightly less than 125 W
• BSlightly greater than 125 W
• CExactly 125 W
• D250 W
Correct Answer : (B)

Slightly greater than 125 W

Explanation:

10.In an electric kettle water boils in 10 minutes. It is required to boil the boiler in 15 min, using the same supply mains

• ALength of heating elements should be decreased
• BLength of heating element should be increased
• CLength of heating element has no effect on heating of water
• DNone of the above
Correct Answer : (A)

Length of heating elements should be decreased

Explanation:

11.Resistance of a material always decrease if

• ATemperature of material is decreased
• BTemperature of material is increased
• CNumber of free electros available becomes more
• DNone of the above is correct
Correct Answer : (C)

Number of free electros available becomes more

Explanation:

12.When electric current passes through a metallic conductor, its temperature rises. This is due to

• ACollisions between conduction electrons and atoms
• BThe release of conduction electrons from the parent atom
• CMutual collision between metal atom
• DMutual collision between conducting electron
Correct Answer : (A)

Collisions between conduction electrons and atoms

Explanation:

13.A glass rod when rubbed with silk cloth is charged because

• AIt takes in proton
• BIts atoms are removed
• CIt gives away electrons
• DIt gives away positive charge
Correct Answer : (C)

It gives away electrons

Explanation:

14.It becomes more difficult to remove

• AAny electrons from the orbit
• BFirst electrons from the orbit
• CSecond electron from the orbit
• DThird electron from the orbit
Correct Answer : (D)

Third electron from the orbit

Explanation:

15.When the leg of parallel circuit is opened out, the total current will be

• AReduce
• BIncrease
• CDecrease
• DBecome zero
Correct Answer : (C)

Decrease

Explanation:

16.Resistance of carbon filament lamp ?? as the applied voltage increases.

• AIncreases
• BDecreases
• CRemain same
• DNone of above
Correct Answer : (B)

Decreases

Explanation:

17.For testing appliances, the wattage of test lamp should be

• Avery low
• Blow
• Chigh
• Dany value
Correct Answer : (C)

high

Explanation:

18.A field of force can be exist between

• ATwo molecule
• BTwo ions
• CTwo atoms
• DTwo metal particles
Correct Answer : (B)

Two ions

Explanation:

19.A substance whose molecules consists dissimilar atom is called

• ASemi-conductor
• BSuper-conductor
• CCompound
• DInsulator
Correct Answer : (C)

Compound

Explanation:

20.Three identical resistors are first connected in parallel and then in series. The resultant resistance in first combination to the second will be

• A9 times
• B1/9 times
• C1/3 times
• D3 times
Correct Answer : (B)

1/9 times

Explanation: