Eletrical And Electronic Principles

Question 1

What is electrical energy

Answer 1

Energy caused by the movement of electrons from one atom to another
Energy=power x time

Question 2

What is electrical power

Answer 2

The rate at which electrical emergency is transferred. It’s measured in watts
P=e/t
P=i x V
P= I2 x R

Question 3

What is electrical force

Answer 3

The attractive or repulsive interaction between any two charged objects

Question 4

What is capacitance

Answer 4

The ability of a circuit or component to store electrical charge
Measured if farads

Question 5

What is the main purpose of a capacitor

Answer 5

To store charge for various applications, such as timing, filtering and supplying electrical energy.

Question 6

What is the magnetic field

Answer 6

The area surrounding a magnet where magnetic force are observable

Question 7

What is the magnetic flux

Answer 7

The total magnetic field that passes through a given area

Question 8

What is the magnetic flux density

Answer 8

The amount of magnetic flux that passes through a given area at right angles to the magnetic field.
Measured in teslas

Question 9

What is electromagnetic induction

Answer 9

When a magnet moves within a coil of wire, it produces voltage. The direction can be reversed by moving the magnets. This is how transformers and generators to work

Question 10

What is used to measure electricity system

Answer 10

Multimeter

Question 11

What is voltages unit of measurement

Answer 11

Volts

Question 12

What is resistance unit of measurement

Answer 12

Ohms

Question 13

What is current unit of measurements

Answer 13

Ampere

Question 14

What is power unit of measurement

Answer 14

Watt

Question 15

What is capacitance unit of measurement

Answer 15

Farad

Question 16

What is inductance unit of measurement

Answer 16

Henry

Question 17

What is energy’s unit of measurement

Answer 17

Joules

Question 18

What is times unit of measurement

Answer 18

Seconds

Question 19

What is frequency’s unit of measurement

Answer 19

Hertz

Question 20

What is magnetic flux unit of measurements

Answer 20

Weber

Question 21

What is magnetic flux density unit of measurement

Answer 21

Tesla

Question 22

What is AC current

Answer 22

Alternating AC changes direction periodically and is sued for mains electricity applications and in high-voltage power distribution

Question 23

What is DC current

Answer 23

Only flows in a single direction and is typically used in low voltage electronic circuit boards and programmable microcontroller-based applications

Question 24

What is Kirchhoff current law

Answer 24

The total current or change entering a node is equal to the charge leaving to node. This is because it has nowhere to go, as none of it is lost within the node

Question 25

What is Kirchhoff’s voltage law

Answer 25

In any closed-loop network, the total voltage around the loop is quality to the sum of all the voltage drops within the loop. This means that the sum of all the voltages within the loop must be equal to zero.

Question 26

What are two types of circuit protection systems

Answer 26

Lightning arrestors, differential protection system, fuses, circuit breakers, distance protection system, RCD’s

Question 27

How do lightning arrestors work

Answer 27

Used to protect power transmission lines,systems, and components from lighting strikes. They do this via height-voltage and ground terminals, which divert the current from the strike to earth

Question 28

How do differential protection systems work

Answer 28

Used to protect transmission lines. They compare the current entering the line with the current leaving it and trip the power if the difference is too great.

Question 29

How do fuses work

Answer 29

They have an internal metal strip of wire that melts when too much current flows through it, this breaks the circuit, preventing any further flow. They are also cheap and easy to source

Question 30

How do circuit breakers work

Answer 30

They use contacts that open when too much current is detected, to interrupt the flow of current.

Question 31

What is the advantages of circuit breakers

Answer 31

They can be reset and used again without replacement, but they do cost more to purchase and install.

Question 32

How do distance protection systems work

Answer 32

They measure the impedance to the AC current between a relay and a fault location, and compare this with a set value, if the measured value is less than this set value, the relay actuates and electrically operated switch and isolates the fault

Question 33

What is an residual current devices (RCDs)

Answer 33

These are often installed in consumer units (fuse boxes) and are designed to protect people from coming into contact with electricity. If there is an imbalance between the neutral and live wires in a circuit, the RCD trips and the power supply is cut off

Question 34

What’s the equation for resistors in a series

Answer 34

R= R1+R2

Question 35

What is the equation for resistors in parallel

Answer 35

(1/R)= (1/R1)+(1/R2)

Question 36

What’s the equation for capacitors in a series

Answer 36

(1/C)= (1/C1)+(1/C2)

Question 37

What is the equation for capacitors in parallel

Answer 37

C= c1+c2

Question 38

What is the equation for inductors in series

Answer 38

L= L1+L2

Question 39

What is the equation for inductors in parallel

Answer 39

(1/L)= (1/L1)+(1/L2)

Question 40

What is a semiconductor

Answer 40

Materials that conduct current better than insulators but not as well as conductors. They are in phones, computers and the internet

Question 41

What is a N-type semiconductor

Answer 41

Electrons are the majority charge carriers.

Question 42

What is a P-type semiconductor

Answer 42

Electrons are the minority carriers

Question 43

What is an example of a P-N junction

Answer 43

A diode

Question 44

How dose a diode work

Answer 44

It allows current to flow from the positive end (anode) to the negative end (cathode) when a positive voltage is applied to the P-type side of the junction.

Question 45

What is forward bias

Answer 45

When current cannot flow in the opposite direction

Question 46

What is reverse bias

Answer 46

When a diode is connected the opposite way around, with a positive voltage applied to the N-type side of the junction. In this configuration, no current cannot flow until the electric field intensity is so high that the diode breaks down.

Question 47

What is an analogue signal

Answer 47

Continuous signals, usually represented as sine waves

Question 48

What is digital signals

Answer 48

Discrete signals, usually represented a square waves

Question 49

What is fan in

Answer 49

Refers to the number of inputs that a logic fate is capable of handaling safely

Question 50

What is fan out

Answer 50

The number of logic gate inputs that are driven by the output of another logic gate