Please enable JavaScript.
Coggle requires JavaScript to display documents.
Electrical Systems - Coggle Diagram
Electrical Systems
Resistance
-
-
-
The higher the resistance, the higher the potential difference needed to move the electric charge through the electrical component
-
-
-
Parallel circuit
net resistance decreases as there are more paths for current to pass through, total current is the sum of each branch
-
-
Voltmeter
Potential difference
-
-
pd between any two points is the amount of energy needed to move one unit of electric charge from one point to another
-
-
-
-
Has to connected parallel to electrical component, does not measure all electrical components unless as stated above
Electricity in Singapore
unit cost is pegged to fuel price and price of natural gas, hence it fluctuates according to the global price of fuel and price of natural gas from Malaysia and Indonesia
-
25.82 cents per unit, with unit referring to kilowatt hour
Electrical appliance
-
time factor and wattage affects amount of electrical energy used, but more appropriate to discuss energy usage in terms of power
Power of an electrical component - amount of electrical energy that is converted to other forms of energy per unit time by electrical component
-
Hazards of Electricity
Electrical fires
-
Overloading
draws large current, generating heat and melting insulation, causing a fire
-
Prevent electrocution
Switch off appliances and pull plug out when in contact with water, never use near water source
-
repair or replace when insulation of electrical wiring is peeled off, as it exposes wires
-
never overload electrical outlet, as it generates much current and heat, melting insulation
Electrical Safety
Three pin plug
-
-
-
-
Scenario: If live wire touches the metal casing and appliance is switched on, the current flows from the live wire to the ground. Low resistance results in high current. Fuse will melt to disconnect the circuit or the Earth Leakage Circuit Breaker will trip to disconnect household electricity supply
Scenario, electrical fault: Live wire touches the metal casing, electricity will not go to the earth
- Switch close 2. Current flows through metal casing to the earth 3. Electrical resistance along wire is very low (close to zero) 4. Current becomes very high and exceed fuse rating 5. Fuse melts 6. Circuit is disconnected from mains
-
-
Flow of Electricity
-
Electric current
measured by the amount of electric charge flowing through any point in a closed circuit per unit time
-
-
-
-