Electricity Parallel and Series Circuit (HBL 2) • Electric Circuits • What makes a Bulb brighter?
May 19, 2015
Electricity Parallel and Series Circuit (HBL 2)
• Electric Circuits• What makes a Bulb brighter?
Electric Circuits
• Closed Circuit
Electric current flows through it.
• Open Circuit
There is a break.
Electric current does not flow through it.
Electric Circuits
• Circuit diagrams record the components and connections of a circuit in a simple and clear way.
• Basic Circuit symbols:
battery
2 batteries
wireswitch
bulb
Components of an Electric Circuit
• Actual circuit versus Circuit diagrambattery
wire
battery holder
switchbulb
battery
wire
switch bulb
In a circuit, the brightness of a bulb depends on:
a) The number of batteries used(the greater the number of batteries, the brighter the bulb).
b) Arrangement of components of the circuit.
Factors that affect the brightness of a bulb:
1. The number of batteries (in series)
Single battery Multiple batteries
dimmer brighter
More ……
• As more batteries are added in series, more current is available and the bulbs become brighter.
• When too many batteries are added, the current is so great that one of the bulbs may blow/fuse (too much heat is made by the filament that it burns out).
Factors that affect the brightness of a bulb:
2. The arrangement of batteries
Batteries arranged in parallel
Batteries arranged in series
dimmer brighter
More ……• Batteries need to be connected with the poles
in the proper direction for current to flow – positive end of one battery needs to be joined to the negative end of another.
• When the number of components is the same, the bulb of the circuit with batteries arranged in series is brighter than that in parallel.
• However, if one battery is removed, only the bulb of the circuit with batteries arranged in parallel remains lighted up.
Factors that affect the brightness of a bulb:
3. The number of bulbs
Single bulb Multiple bulbs
brighterdimmer
More ……
• The greater the number of bulbs, the dimmer they are.
Bulbs arranged in Parallel
Bulbs arranged in Series
Factors that affect the brightness of a bulb:
4. The arrangement of bulbs
brighter dimmer
Bulbs in series vs Bulbs in parallel
Points for comparison
Arrangement of bulbs in:
Series Parallel
Number of paths for the electric current
Only one path; current passes through
components one after another
2 or more paths; current splits up and
passes through each branchat the same time;
paths are independent of each other
Brightness of bulbs
Dimmer Brighter
If one bulb is removed or damaged
Electric current cannot flow through the circuit, the
remaining bulb will not light up
Electric current can still flow through the other path and the
other bulb still lights up
Application - Used in the connection of circuits in the houses; twinkling lights, bumper cars in fun fairs
Application ……• All the lights in our houses were
connected in series, then we have to turn on all the lights at the same time. If one bulb blows, then all the bulbs will not light up. Hence household lighting and wiring is arranged in parallel. Each bulb has an individual switch to control it.
• Christmas Tree lightings
The End