4 matching electric source & load

CHAPTER 8.THE BENEFITS and

DANGERS OF ELECTRICIAL ENERGY

Electricity: An In-Demand Form of EnergyElectricity provides us

many valuable things that without it we would live a hard and difficult

life day by day.Despite its many

benefits, electricity could bring danger as well from the most common house

fires to electrocution, which may lead to death.

Why can’t a 1.5 dry cell light up a 4.5V bulb?

Matching Electric Source & LoadWhy is a 110V TV set

damage when plugged into a 220V source?

1.5V

All electrical energy appliances are designed to work efficiently at a certain voltage. This is its voltage rating. It is usually written

at the back of an appliance.

Knowing what these label mean helps a person use the electrical appliances

properly; reducing the risks of accidents.

Matching Electric Source & Load

Here is an example:

Voltage:Voltage:Watt Rating:Watt Rating:

Current Rating:Current Rating:

22022065650.50.5

65 WATTS 220VAC, 0.5 amperes




2202200.36kWh/24h0.36kWh/24h

0.70.7

220VAC

0.7 amperes

60 Hz

0.36 kWh/24h




22022060602.02.0

60 W220VAC 60Hz

2.0A




220220

6A6A

220VAC / 60Hz

6A/220V220VA

220VAC / 60Hz




220220580580

33




220220

330A330A


The following labels indicate that the appliances

operates normally and efficiently on the specified

values.If connected to a lower

voltage source, it will not work efficiently. The electric

current through these appliances will not be

enough.Connecting them to a large

amount of current will cause a damage and hamper their normal

operations.


Some appliances, like flashlights, portable radios,

and calculators are designed to operate on

direct current (DC). Batteries supply direct

current to such appliances.Unless an AC-DC converter is used, these appliances

should not be connected to a wall outlet.



Identify the voltage, wattage and current rating

of the following:

110VAC

1.7 amperes

60 Hz

0.36 kWh/24h


80 W115VAC 60Hz

1.0A


220VAC / 60Hz

5A/220V220VA

110VAC / 60Hz


Answers to the exercises…


Identify the voltage, wattage and current rating

of the following:



23023065651.51.5



1101100.36kWh/24h0.36kWh/24h

1.71.7

110VAC

1.7 amperes

60 Hz

0.36 kWh/24h




11511580801.01.0

80 W115VAC 60Hz

1.0A




110110

5A5A

220VAC / 60Hz

5A/220V220VA

110VAC / 60Hz




220220580580

33




2302303030


4 matching electric source & load

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