Basic Electrical Special MCQ Part Two
1.A positive electric pole
- Has a deficiency of electrons.
- Has fewer electrons than the negative pole.
- Has an excess of electrons.
- Has more electrons than the negative pole
Answer-2
2.An EMF of one volt
- Cannot drive much current through a circuit.
- Represents a low resistance.
- Can sometimes produce a large current.
- Drops to zero in a short time.
Answer-3
3.A potentially lethal electric current is on the order of
- 0.01 mA.
- 0.1 mA.
- 1 mA.
- 0.1 A.
Answer-4
4.A current of 25 A is most likely drawn by
- A flashlight bulb.
- A typical household.
- A power plant.
- A clock radio.
Answer-2
5.Which of these can represent magnetomotive force?
- The volt-turn.
- The ampere-turn.
- The gauss.
- The gauss-turn.
Answer-2
6.Which of the following units can represent magnetic flux density?
- The volt-turn.
- The ampere-turn.
- The gauss.
- The gauss-turn.
Answer-3
7.A ferromagnetic material
- Concentrates magnetic flux lines within itself.
- Increases the total magneto motive force around a current-carrying wire.
- Causes an increase in the current in a wire.
- Increases the number of ampere-turns in a wire.
Answer-1
8.A coil has 500 turns and carries 75 mA of current.The magneto motive force will be
- 37,500 At.
- 375 At.
- 37.5 At.
- 3.75 At.
Answer-3
9.A piece of wire has a conductance of 20 siemens. Its resistance is
- 20 Ω.
- 0.5 Ω.
- 0.05 Ω.
- 0.02 Ω.
Answer-3
10.A resistor has a value of 300 ohms. Its conductance is
- 3.33 millisiemens.
- 33.3 millisiemens.
- 333 microsiemens.
- 0.333 siemens.
Answer-4
11.A mile of wire has a conductance of 0.6 siemens. Then three miles of the same wire has a conductance of
- 1.8 siemens.
- 1.8 Ω.
- 0.2 siemens.
- Not enough information has been given to answer this.
Answer-3
12.A 2-kW generator will deliver approximately how much current, reliably, at 117 V?
- 17 mA.
- 234 mA.
- 17 A.
- 234 A.
Answer-3
13.A circuit breaker is rated for 15 A at 117 V. This represents approximately how many kilowatts?
- 1.76.
- 1760.
- 7.8.
- 0.0078.
Answer-1
14.You are told that a certain air conditioner is rated at 500 Btu. What is this in kWh?
- 147.
- 14.7.
- 1.47.
- 0.147.
Answer-4
15.Of the following energy units, the one most often used to define electrical energy is
- The Btu.
- The erg.
- The foot pound.
- The kilowatt hour.
Answer-4
16.The frequency of common household ac in the U.S. is
- 60 Hz.
- 120 Hz.
- 50 Hz.
- 100 Hz.
Answer-1
17.Half-wave rectification means that
- Half of the ac wave is inverted.
- Half of the ac wave is chopped off.
- The whole wave is inverted.
- The effective value is half the peak value.
Answer-2
18.In the output of a half-wave rectifier
- Half of the wave is inverted.
- The effective value is less than that of the original ac wave.
- The effective value is the same as that of the original ac wave.
- The effective value is more than that of the original ac wave.
Answer-2
19.In the output of a full-wave rectifier
- The whole wave is inverted.
- The effective value is less than that of the original ac wave.
- The effective value is the same as that of the original ac wave.
- The effective value is more than that of the original ac wave.
Answer-3
20.A low voltage, such as 12 V
- Is never dangerous.
- Is always dangerous.
- Is dangerous if it is ac, but not if it is dc.
- Can be dangerous under certain conditions
Answer-4