Module 3 quiz contains 52 question based on the syllabus for module 3 examination for B1.1, B1.3 and B2 category.

The time limit for the quiz is 65 min.

The number of attempts allowed are unlimited.

All the best.

Name

1.

Wave and Lap windings are designed to give:

high ripple and low ripple respectively

high voltage and high current respectively

high current and high voltage respectively

None

2.

In a magnetic circuit:

air has a higher reluctance than soft iron

more length of coil produces less field intensity for a specified mmf

more reluctance means more flux for a specified mmf

None

3.

The current in a circuit is 6 amps the amount of charge moved in 25 seconds is:

4.16 coulombs

150 coulombs

0.24 coulombs

None

4.

A capacitor consists of

Two insulators

Two dielectrics

Two semiconductors

Two conductors

None

5.

When making up electrolyte for lead acid batteries:

it is safest to add acid to water

equal quantities of water and acid should be used

it is safest to add water to acid

None

6.

An eight pole generator rotates at 6,000 RPM. The frequency produced is:

1200 Hz

400 Hz

800 Hz

None

7.

One unit of Potential Difference is:

equal to one joule of work per coulomb of charge

inversely proportional to the resistance in the circuit

a movement of 6.25 x10^18 electrons between 2 points

None

8.

In order to produce a substantial voltage and current from photovoltaic cells they should be connected in:

parallel with each other

series parallel arrangement

series with each other

None

9.

5 amps passes through a 4 ohm resistor, the amount of power the resistor has to dissipate is:

6.25 watts

20 watts

100 watts

None

10.

Find the current in the circuit

1 A

3 A

2 A

None

11.

Diamagnetic materials have a permeability of:

much greater than 1

slightly less than 1

slightly greater than 1

None

12.

In an inductive circuit, the current________ the voltage?

Leads

is less than

is greater than

Lags

None

13.

A 10 centimeter rod of specific resistance 0.5 and a cross sectional area of 1 centimeter, has a resistive value of:

2 Ω

5 Ω

1 Ω

None

14.

Friction can induce electrostatic charge of very:

high voltage on conducting surfaces

high voltage on insulated surfaces

ow voltage on insulated surfaces

None

15.

Connecting two 28volt 60 Amp/Hour batteries in parallel will produce:

56V 60A/H

28V 120A/H

28V 60A/H

None

16.

A potentiometer is a:

Terminal device used to vary current

2 terminal device used to vary voltage

3 terminal device used to vary voltage

None

17.

An alternating current voltage waveform has a root mean square value of 70.7 volts the peak voltage is:

56 Volts

200 volts

100 volts

None

18.

Which among the following expressions relate charge, voltage and capacitance of a capacitor?

Q=V/C

Q=C/V

Q=CV

None

19.

A coil has an inductance of 8 mH with 125 turns. When the number of turns is doubled within the same length, the inductance will become:

4 mH

32 mH

16 mH

None

20.

Some materials emit electrons to a light source. These are:

Photovoltaic cells

Thermoelectric cells

Piezoelectric cells

None

21.

An electromagnet of resistance 16ohm requires a current of 1.5A, the voltage required is:

18V

24V

11V

None

22.

If 2V is supplied to a 3F capacitor, calculate the charge stored in the capacitor

6C

3C

1.5C

None

23.

If four Identical cells of 2.2 volt and 15 amp/hour (A/H) capacity are connected in series the voltage and A/H will be:

8.8V 60A/H

2.2V 15A/H

8.8V 15A/H

None

24.

In shaded pole induction motor if the supply current is reversed the motor will:

stop

change direction

maintain direction

None

25.

Which of the following is a passive device?

Transistor

Rectifier

Capacitor

None

26.

If there are two bulbs connected in series and one blows out, what happens to the other bulb?

The other bulb also burns out

The other bulb continues to glow with the same brightness

The other bulb glows with increased brightness

The other bulb stops glowing

None

27.

None

28.

Calculate the time constant of a series RC circuit consisting of a 100microF capacitor in series with a 100ohm resistor.

0.1 sec

0.1 msec

0.01 msec

0.01 sec

None

29.

The point of coercivity occurs when the:

magnetic flux is zero even though a magnetising force is being applied

magnetic force reaches its peak positive of negative value

magnetic force applied causes the material to become magnetically saturated

None

30.

A 12V battery has an internal resistance of 0.2 ohm. With a 5A load current flowing what is the potential difference of the battery?

1V

11V

12V

None

31.

If the output of a generator drops from 100V with zero current flowing to 80V with 2A flowing then the internal resistance is:

90 ohm

10 ohm

120 ohm

None

32.

When capacitors are connected in parallel, what happens to the effective plate area?

Becomes zero

Decreases

Increases

Remains the same

None

33.

The two factors which govern the output frequency of an AC generator are the:

strength of the stator field flux and number of poles

speed of rotation of the rotor and the stator field flux strength

the number of poles (in pairs) and the rotor RPM

None

34.

The most common form of primary cell is:

a lead acid cell with the terminals of lead peroxide and spongy lead giving 2.1V

the zinc carbon where carbon is positive zinc is negative and the output is 1.5V

made from nickel cadmium with a potential of 2V between the plates

None

35.

What is the value of capacitance of a capacitor which has a voltage of 4V and ha 8C of charge?

4F

2F

8F

None

36.

The power factor of an alternating current circuit is:

the cosine of the phase angle

the tangent of the phase angle

the sine of the phase angle

None

37.

When two resistors are connected in series:

They must both have the same resistance value

the voltage across each will be the same

the current through each will be the same

None

38.

The voltage rating on a capacitor is the:

voltage at which the dielectric breaks down if exceeded

maximum reverse voltage before the plates buckle

voltage that the capacitor becomes saturated and will accept no more charge

None

39.

Capacitor is a device used to

store magnetic energy

vary the resistance

store electrical energy

None

40.

The generator characteristic of:

low current and high voltage are found in a lap winding format

high current and low voltage are found in a lap winding format

high current and low voltage are found in a wave winding format

None

41.

When a circuit contains both a resistor and an inductor a phase angle is developed between current and voltage, such that:

the voltage lags the current by >45 degrees

the voltage lags the current by <90 degrees

the voltage leads the current by <90 degrees

None

42.

The Electron Valence of an Element with 5 electrons is:

1

3

5

None

43.

Calculate the MMF (Magneto Motive Force) of a coil with 2000 turns and a 5mA current:

10

20

5

None

44.

If an EMF (Electromotive Force) of 120V is applied to a circuit of three equal value resistors in series and a current of 2A flows, the value of total resistance is:

20 ohm

60 ohm

80 ohm

None

45.

If in an alternating current circuit, impedance is 26 ohm, capacitive reactance is 24 ohm, what is the resistance?

2 ohm

25 ohm

10 ohm

None

46.

In a lead acid cell, there are:

more negative than positive plates

an equal number of plates

more positive than negative plates

None

47.

If a pure capacitance and a pure inductance of equal reactance are in series the supply current is:

Out of phase with the voltage

in phase with voltage

less than 90° to the voltage

None

48.

A battery of 18V with an internal resistance of 1.5Ω is connected in a circuit with three resistors in parallel of values 6Ω, 12Ω and 12Ω. The total circuit resistance is:

12Ω

4.5Ω

31.5Ω

None

49.

RMS stands for

Root Minimum Square

Root Mean Square

Root Maximum square

Root Mean Sum

None

50.

A component is required to give a negative temperature coefficient value. It is likely to be made of:

copper

aluminium

carbon

None

51.

The retentivity of a material is given by

Remanence / Coercive Force

Coercive Force / Remanence

Coercive Force x Remanence

None

52.

In the Diagram the two unknown resistors are of equal value and their value is: