Test Your Skills in Electrical Engineering

1.

1 point

What is the property of material to resist the flow of current?

conductance

resistance

admittance

susceptance

2.

3 points

The resistivity of copper is _ _._ x 10 exp (-9) ohm-meter @20 degC.

3.

3 points

When two materials of different composition are joined together to form one loop. When each of its junctions are exposed into different temperatures, the current will flow. This electrical phenomenon is called _________ effect.

4.

1 point

To produce an 800 Hz sine wave, a four-pole generator must be operated at _____? Express your answer in rev/sec.

2400

400

800

1600

5.

1 point

One sine wave has a positive-going zero crossing at 15° and another sine wave has a positive-going zero crossing at 55°. The phase angle between the two waveforms is? Express your answer in degrees.0

0

45

40

none of the above

6.

1 point

If a sine wave goes through 10 cycles in 20 micro-sec, the period is ______ micro-sec?

2

4

20

100

7.

1 point

What kVA rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kV?

4 KVA

.25 KVA

8 KVA

16 KVA

8.

1 point

The primary of a transformer is connected to a 6 V battery. The turns ratio is 1:3 and the secondary load, RL, is 100 ohms . The voltage across the load is

24 V

0 V

2 V

18 V

9.

1 point

In a certain three-wire Y-connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages are ____ V?

2000

3000

666

3464

10.

1 point

In a Delta-connected source feeding a Y-connected load,

each phase voltage equals the difference of the load voltages

each phase voltage equals the corresponding load voltage

each phase voltage is one-third the corresponding load voltage

each phase voltage is 60° out of phase with the corresponding load voltage

11.

1 point

The minimum resistance value for a blue, gray, red, silver resistor is _____ ohms.

612

620

6800

6460

12.

1 point

A 33 ohms half-watt resistor and a 330 ohms half-watt resistor are connected across a 12 V source. Which one(s) will overheat?

33 ohms

330 ohms

both resistors

neither resistors

13.

1 point

A certain appliance uses 350 W. If it is allowed to run continuously for 24 days, how many kilowatt-hours of energy does it consume? express in KWh

20.16

201.6

2.01

8.4

14.

1 point

A two-phase generator is connected to two 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?

1.33

1.88

2.66

1.77

15.

1 point

One eV is equal to _ . _ _ x 10 exp(-19) J

6.02

1.60

6.25

1.66

16.

1 point

What is the range of the operating voltage level for LEDs?

5-12 mV

1.7-3.3 V

5- 12 V

20 - 25 V

17.

1 point

Which of the following equipment can check the condition of a transistor?

current tracer

digital display meter

ohmmeter (VOM)

all of the above

18.

1 point

The induced voltage across a coil with 250 turns that is located in a magnetic field that is changing at a rate of 8 Wb/s is ___ volts?

1000

2000

31.25

3.125

19.

1 point

A 4.7 Mega-ohm resistor is in series with a 0.015 micro-F capacitor. The combination is across a 12 V source. How long does it take the capacitor to fully charge?

35 ms

352 ms

3.5 s

1.23 ms

20.

1 point

A sine wave voltage is applied across a capacitor. When the frequency of the voltage is decreased, the current

increases

remains constant

decreases

ceases