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Just in case you are wondering what MESS is about,
it is a collaborated educational blog.

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This blog is officially opened in 21 August 2009




-10 Recent Posts-
P5 Science Chapter 4: Reproduction in Plants
Primary 5 Science Chapter 2 :Cells
P5 Science Chapter 1 :The Solar System
P4 Science chapter 7: Heat
P4 Science Chapter 6: Energy & Light
P4 Science Chapter 5: Circulatory System
P4 Science: Air & the Respiratory System
P4 Chapter 3: The Water Cycle & Importance of Water
P4 Chapter 2: Water and Changes of States
P4 chapter 1: Matter & its 3 states


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Thursday, August 27, 2009
P5 Science Chapter 6: Electricity @ 3:34 PM

0.Lyn's Note to all: We've already gone through Respiration & Photosynthesis in P4, so I don't wanna nag -.- If you want to find out, just click on P4 Air & Respiratory System)

P5 Science Chapter 6: Electricity

Main Sources of electricity: Power Stations, Batteries

Other sources:

(Sun)Light energy -> Electrical Energy

(Wind)Kinetic energy -> electrical energy

(water) Kinetic energy -> electrical energy

Geothermal sources, nuclear energy, tidal waves

1. Electric Circuits
  • a battery has a postive & negative pole
  • A bulb will light up if the circuit is closed & electricity can flow through
  • the wires MUST be connected to the TIP and METAL CASE of the bulb
  • A bulb's filament is made of tungsten
  • Factors's affecting brightness of bulb (BOB) :

~No. of batteries ( The more the brighter)

~Arrangement of batteries (Series/ Parellel)

~Arrangement of bulbs (Series/ Parallel)

~No. of bulbs (The more the dimmer)

Parts of a light bulb

# Glass bulb

  • Is made from a piece of hot glass that is blown into a shape.
  • Prevents filament from being damaged.
  • Does not contain air (Vacuum) because tungsten may easily catch fire especially if oxygen is present.
# Filament
  • Made of a metal called tungsten
  • Tungsten has a very high melting point of 3422 degree celcius! (If your filament fuses, how hot it is inside the bulb?)
  • It is able to glow (light) without melting when an electric current flows through it.
# Stiff metal wires
  • Make contact with both ends of the filament and metal contacts at the metal casing and the tip of the light bulb.
  • They conduct the electric current from the metal contacts to the filament, so that the light bulb can light up.
# Metal casing
  • It must be connected to one end of a wire in an electric circuit so that the bulb will light up.
  • Made of metal so that electricity can flow through.
  • Often shaped such that the light bulb can be screwed onto a light bulb holder.
# Metal tip
  • Must be connected to the other end of a wire in an electric circuit to complete the circuit.



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