ELECTRICAL THEORY

Question 1

It is the presence and flow of electric charge

Answer 1

Electricity

Question 2

Electrical Classification of Materials

Answer 2

Electrical Conductors
Electrical Insulators
Electrical Semiconductors

Question 3

Electrical Conductors

Answer 3

these are materials that allow the essentially free passage of current when connected to a battery or other source of electrical energy.

Question 4

Electrical Insulators

Answer 4

these are materials that possess low conductivity or offer a relatively high resistance to the flow of electric current. They are also called as dielectrics.

Question 5

They are also called as dielectrics.

Answer 5

Electrical Insulators

Question 6

Electric Semiconductors

Answer 6

these are materials that have conductivity about midway between good conductors and good insulators.

Question 7

Source of Electric Current

Answer 7

1. Static electricity from friction
2. Thermoelectricity is electricity from heat
3. Piezoelectricity is electricity from pressure
4. Electrochemistry is electricity from light
5. Magnetoelectricity is electricity from magnetism

Question 8

Fundamentals Unit of Electricity

Answer 8

1. Voltage or electromotive force (E or EMF)
2. Amperage or Inductive Flow (I)
3. Resistance

Question 9

Voltage or electromotive force (E or EMF)

Answer 9

_It is the driving force behind current flow. The unit of
electrical pressure is the volt (V).
_Voltage level governs the amount of electrical energy that will flow through a wire.
_A boost in voltage increases current flow and a drop in voltages reduces flow

Question 10

Amperage or Inductive Flow (I)

Answer 10

it is the rate of current flow in a closed electrical system is measured in a unit called the ampere, frequently called the amp.

Question 11

___ governs the amount of electrical energy that will flow through a wire

Answer 11

Voltage level

Question 12

Resistance

Answer 12

-It is the property of a material that limits the amount of flow of current and converts electric energy to heat energy. Its unit is the Ohm.
-The length of a conductor (wire), the diameter of the conductor, type of conductor material, and temperature of the conductor affect the resistance to flow of current.

Question 13

Ohm’s Law

Answer 13

“At steady-state condition, the voltage across a resistor is directly proportional to the current flowing through it with the temperature remaining constant.”

Question 14

Ohm’s law
V –
I –
R –

Answer 14

V – applied voltage in volts
I – current drawn in amperes
R – resistance in ohms

Question 15

Conditions for Ohm’s Law

Answer 15

1. Ohm’s law can be applied either to the entire circuit or a part of a circuit.
2. When Ohm’s law is applied to a part circuit, part resistance and the potential differences across that part resistance should be used.
3. Ohm’s law can be applied to both dc and ac circuit.

Question 16

Limitations of Ohm’s Law

Answer 16

Ohm’s law is not applicable to the following:
1. For metal which get heated up due to the flow of current through them.
2. For electrolytes where enormous gases are produced on either electrode.
3. For vacuum radio valves.
4. For arc lamps.
5. For semiconductors
6. For gas-filled tubes, in which the ions are generated as a result of current flow.
7. For appliances such as metal rectifier and crystal detectors, in which the operation depends on the direction
of current.

Question 17

It is the rate at which work is accomplished; it is work or energy released divided by time.

Answer 17

Electrical Power

Question 18

It is the rate electric charge converted into another form, such as light, heat or mechanical energy (or converted from another form into electrical energy). Its unit is the Watt (W)

Answer 18

Electrical Power

Question 19

Energy

Answer 19

It is the capacity to do work. It is measured in Joules (J)

Question 20

Electrical Energy Consumption

Answer 20

It is the rate at which power is consumed over a specified period of time.

Question 21

Electrical Energy Consumption Formula

Answer 21

E=Pt

Question 22

Electric Circuit

Answer 22

-It is the collection of electrical elements interconnected in some specific way through which electric current
flows or it is intended to flow.
-A circuit is consisting of a source, conducting parts and a load

Question 23

Closed Circuit

Answer 23

_It is an uninterrupted path that allows a continuous flow of current through an electrical circuit.
_In a building electrical system, a circuit is closed when a switch is turned on, allowing current to flow uninterrupted and the lamp to light.

Question 24

Open Circuit

Answer 24

If the path of current flow is interrupted such as if the switch in a circuit is opened (turned off), an open circuit
results.

Question 25

Short Circuit

Answer 25

_If an inadvertent shortcut develops in a circuit that permits current flow through an unintentional path, a short
circuit is created.
_A short circuit occurs when current leaks out of the intended conductor path such as out of a wire
with damaged insulation.

Question 26

occurs when current leaks out of the intended conductor path such as out of a wire with damaged insulation.

Answer 26

A short circuit

Question 27

2 BASIC TYPE OF Circuiting Configurations

Answer 27

Series Circuit
Parallel Circuit

Question 28

Series Circuit

Answer 28

the circuit elements are said to be connected in series when they all carry the same current.

Question 29

Properties of Series Circuit

Answer 29

a. The same current flows through all the resistance
b. There will be voltage drop across each resistance
c. The sum of the voltage drop is equal to the applied voltage

Question 30

Parallel Circuit

Answer 30

circuit elements are connected in parallel when the same voltage is common to all of them.

Question 31

Properties of a Parallel Circuit

Answer 31

a. The voltage across each resistance of the parallel combinations is the same.
b. There are as many current paths as the number of branches
c. The current in each branch is given by Ohm’s law
d. The total current of the circuit is equal to the sum of branch currents.

Question 32

P=W/t

Answer 32

Electrical power Formula