Current Electricity

Question 1

How does an electric current happen

Answer 1

An electric current is caused by the flow of electrons through a good conductor such as a metal

Question 2

How can Electricity Energy be used?

Answer 2

Electrical Energy can be converted into….
• Light
• Heat
• Kinetic • Sound
• Light Energy so we can see in the dark
• Heat energy so we can cook + heat buildings
• Kinetic Energy for electric motors
• SoundEnergyfor music.

Question 3

Closed circuits

Answer 3

A closed circuit is needed for the current to flow.

Question 4

Why would the electric energy not get through if there is a break in the circuit.

Answer 4

A closed circuit is needed for the current to flow.

Question 5

How is a current moved around the circuit?

Answer 5

• Energy provided by a battery or power pack is needed to move the current around the circuit The battery pumps electrons from its negative end around a circuit
• The electrons travel all the way around and are attracted back to the positive end of the battery

Question 6

Resistance

Answer 6

Resistance is the opposition to the flow of electrons. The unit is the Ohm (Ω), and it is measured using an Ohmmeter

Question 7

What happens if a resistor is placed in an electric circuit?

Answer 7

If a Resistor is placed in an electric circuit, it will slow down the flow of electrons

Question 8

What do we need Resistors for?

Answer 8

As the electrons push to get through the resistor the electrical energy is changed to heat energy
• When Resistors such as a light bulb filament or the heating coil of a kettle is placed in a circuit they resist the current and thus get hot

Question 9

What is Ohm’s Law

Answer 9

Ohm’s law states that voltage is directly proportional to current
• V= voltage, I= current, R= resistance

Question 10

W h a t is the p.d. fi the resistance is 102 and the current is 2A?

Answer 10

V=IR = (10)(2) = 20 V.

Question 11

What is the current if the resistance is 2 0 and the p.d. is 6 V?

Answer 11

I=
V 6 =0.3A. 20

Question 12

What are the 3 effects of electricity

Answer 12

Heating- when a light bulb heats up
Chemical- separating hydrogen and oxygen
Magnetic- Making an electromagnet using a nail and a coil wire.

Question 13

how is the current supplied by the ESB.

Answer 13

By Alternating currents:

Alternating current changes very quickly, many times a second
AC can be converted to DC using a rectifier, smoothed using a capacitor