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electrical system - Coggle Diagram
electrical system
drawing circuit diagrams
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battery = two verticle lines (short = negative, long = positive)
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variable resistor = rectangle with diagonal line across, fixed resistor = rectangle
resistance
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higher the resistance, more p.d. needed to move electric charge
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resistors
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arrangement
parallel arrangement = resistance decrease , current flowing increase, bulb brighter
series arrangement = resistance increase, current flowing decrease, bulb dimmer
lower resistance, brighter bulb
higher resistance , dimmer bulb
power
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one watt of power means that in a second, one joule of electrical energy is being converted to other forms of energy
kilowatts (kW), 1 kW = 1000 W
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brightness
brighter bulb = more power, dimmer bulb = less power
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potential difference
basic info
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a positive electric charge always flows from a higher point of potential to a lower point of potential. an electric current can only flow when theres p.d.
the potential between any two points in a circuit is the amount of energy needed to move one unit of electric charge from one point to another
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one volt of p.d. means one joule of energy is needed to move one unit charge . the more energy needed, the greate the p.d between the two points
voltmeter measures amount of volt. must be connected in parallel, negative match negative battery, positive match positive battery
electric current
basic info
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one ampere of current means that one unit of electric charge flows in one second. An electric current is measured by the amount of electric charge moving per unit time past any point in the circuit
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ammeter = measures amount of ampere, must be connected in series and positive match battery positive, negative match battery negative
electric flows
conventional - current flows from positive terminal of battery to negative terminal of battery (starts from left side)
electron - current flows from negative terminal of battery to positive terminal of battery (starts from right)
types of circuit
series - a single loop, electric current passes through a single path
parallel - electric current is divided into branches, electric current passes through all branches
hazards of electricity
electric fires
wires dont not heat up because the components in the circuits resist the flow of electric charge. this ensures that the current is not large
large currents can occur when electrical circuits are damaged, do not work properly or misused
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electric shocks
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example
- wire at high potential is disconnected from heating coil and touches metal casing
- electric potential of casing increases
- large p.d between ground and kettle
- if person touches casing, current flows through his body into the ground
prevention
earth wire
earth wire provides a path of electrical resistance. the large current flows through directly from live wire into ground/earth
fuse
a large current will cause the fuse to melt and cause circuit to beome open. fuse rating should be higher than operating current.
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circuit breaker
there is one main switch to on or off the electricity in household. when any electric items in house is faulty, or too large of a current is passing through the circuits, the circuit will trip to stop current from flowing