electrical fundamentals quiz

Question 1

what is the name of an electrically neutral group of two or more atoms held together by chemical bonds

Answer 1

molecule

Question 2

what is correct about electrical current in a conductor?

Answer 2

when an electron enters a conductor, another electron at the opposite end is pushed out

Question 3

how is voltmeter connected

Answer 3

in parallel with the terminal of a power source and/or a load

Question 4

when electrons move through a conductor. the acceleration lost is turned into which kind of energy?

Answer 4

Thermal energy

Question 5

what does the movement of electrons depends on?

Answer 5

conductor material, conductor cross-sectional, potential difference and temperature

Question 6

where on the aircraft is the electrical field more concentrated

Answer 6

on the trailing edge of the wings, elevators and fins

Question 7

faraday law

Answer 7

when an armature rotates between the magnet’s poles upon an axis perpendicular to the magnetic field, the flux linkages of the armature changes continuously, due to this, an EMF is induced in the armature

Question 7

what is true about voltage generated by friction

Answer 7

they can reach very high values of unto thousands of volts.

Question 8

what happens if a conductor moves through a magnetic filed, and that motion is in some part at right angles to the direction of the field?

Answer 8

an electromotive force (EMF) is induced across the conductor.

Question 9

what happens when there is a current flowing through a voltage generator operating on-load?

Answer 9

the terminal voltage decreases as the current increases.

Question 9

what is the fundamental difference between primary cells and secondary cells?

Answer 9

primary cells are non-rechargeable, secondary cells are rechargeable

Question 10

what does it mean when a battery has a capacity of 50Ah?

Answer 10

it supplies a current of 5A for 10 hours

Question 11

what can Ohm’s law be used for?

Answer 11

to calculate an unknown value for either voltage, current or resistance

Question 12

which law describes the relationship between current and voltage for most conductors?

Answer 12

Ohm’s law

Question 13

in a Wheatstone bridge, what is used to indicate potential difference?

Answer 13

a Galvanometer

Question 14

what is power?

Answer 14

power is the rate at which either work is done or heat is transferred. it is measured in joules per second (j/s), which is also known as watts (W)

Question 15

why should permanent magnets be kept away from external magnetic fields?

Answer 15

to prevent the magnet from becoming de-magnatised

Question 15

what are capacitors capable of doing in a circuit for a short time?

Answer 15

storing charge.

Question 16

what happens when the lines of magnetic flux come closer together?

Answer 16

the magnetic field becomes stronger and there flux density increase.

Question 17

what can be integrated parallel to a coil as a precaution to lower the back electromotive force (EMF)?

Answer 17

freewheeling diodes

Question 18

the action of moving a coil, or loop of wire, through a magnetic field induces a voltage in the coil with a magnitude that is proportional to…

Answer 18

the speed or velocity of the movement

Question 19

how can the rated power output be calculated?

Answer 19

by multiplying a motors rates torque by the rotational speed.

Question 20

two different voltages can be measured in aircraft three-phase systems: one phase referenced to the ground and one measured phase-to-phase. what are the respective voltages?

Answer 20

ground 115v phase to phase: 200v

Question 21

what is the name of the product of the root means square (RMS) values of voltage across the resistance and the current flowing through it?

Answer 21

the true power of the resistance.

Question 21

with what type of connection can a standard three-phaser system be obtained?

Answer 21

Star or Y connection

Question 22

some types of alternating current (AC) are classified according to the shape of the waveform. what does a triangular wave indicate?

Answer 22

a steady rate of change of voltage over each half cycle

Question 23

under what circumstances does the capacitive reactance of a capacitor decrease?

Answer 23

as a capacitance increases, and as the frequency increases.

Question 24

what is the difference between an electrical current through a solid material, and a current through a liquid (electrolyte)?

Answer 24

in the solid, the electrons carry the charge; in the liquid, the ions carry the charge.

Question 25

what is the purpose of a step up transformer and step down transformer?

Answer 25

a step-up transformer increases the voltage and decreases the current; a step-down transformer decreases the voltage and increase the current.

Question 26

name 2 electronic filters

Answer 26

High-pass filter (HPF)
Low-pass filter (LPF)

Question 27

Which type of circuit is used in most aircraft generators?

Answer 27

A three-phase or polyphase circuit.

Question 28

what does am alternating current (AC) square waveform represent?

Answer 28

it is mostly used for representing electrical signals, e.g., voltage circuit outputs and clock signals

Question 29

what is the difference between induction motors and direct current (DC) motors?

Answer 29

changes in load do not affect their speed much but change their torque.

Question 30

which alternation current (AC) motor is typically used as a generator

Answer 30

Synchronous