W HAT IS E LECTRICITY ? Energy possessed by an object when
electricity passes though it. Electricity from power stations
Electricity from batteries Potential energy in fuelskinetic
energyelectrical energy + heat energy Chemical potential energy in
fuelselectrical energy + heat energy
Slide 3
U SES OF E LECTRICITY Light Includes light bulbs, lamps Enables
one to see things clearly LASER Medical, applications;
entertainment value
Slide 4
U SES OF E LECTRICITY Sound from electrical signals into sound
waves
Slide 5
U SES OF E LECTRICITY Heating effect Appliances have a heating
element which heats up and releases heat energy when an electrical
current flows through it.
Slide 6
U SES OF E LECTRICITY Magnetic effect These appliances contain
electromagnets which are made of a wire coiled around a magnetic
material such as iron or steel. When an electric current passes
through the wire, a magnetic field is set up and the magnetic
material can act as a magnet to attract other objects.
Slide 7
E LECTROMAGNETISM AND COMPASS A compass may be used to show the
magnetic effect of an electric current. Needle in a compass is a
magnet; it has a North and a South end. Electric current has a
magnetic field The compass needle deflects in the presence of a
magnetic field set up by an electric current.
Slide 8
ELECTROMAGNETS
Slide 9
F ACTORS AFFECTING THE STRENGTH OF AN ELECTROMAGNET Number of
turns
Slide 10
F ACTORS AFFECTING THE STRENGTH OF AN ELECTROMAGNET Presence of
a magnetic material
Slide 11
F ACTORS AFFECTING THE STRENGTH OF AN ELECTROMAGNET Number of
batteries
Slide 12
U SES OF ELECTROMAGNETS Magnetic cranes Electric Motor Electric
Bell
Slide 13
C ONSERVATION OF E LECTRICITY Why is there a need to conserve
electricity? What do you do to conserve electricity? What
conservation measure do you not practice but wish you can?
Slide 14
P HANTOM P OWER /P OWER V AMPIRISM Based on the video, answer
the following questions 1. What is vampire power? 2. In what ways
is vampire power or phantom power observed? 3. What is the effect
of this phenomenon? 4. What realistic vampire power saving tips are
suggested?