Electrical Safety Guidelines

Study Notes

Damaged electrical cords can lead to fatal electric shocks.
It is vital to know the location of the mains supply for safety.
Keep electrical equipment away from water and wet areas to minimize shock risk.
Avoid taking risks with electricity and troubleshooting electrical appliances without proper knowledge.

Never reset a tripped circuit breaker or replace a blown fuse without identifying and resolving the cause.
Misusing electrical equipment can lead to hazards; keep such devices dry.
Using flammable solvents near electrical apparatus can be dangerous unless labeled “flameproof.”
Use specific types of extinguishers, like carbon-dioxide or dry-powder, for electrical fires.
Switch off power quickly during emergencies.
Avoid overloading circuits by plugging too many devices into one outlet; opt for power boards with individual switches.

An electric circuit is a pathway for current to flow, consisting of:
- A source of electromotive force (emf) like a battery.
- A load, which has resistance, such as a lamp.
- Conductive wires connecting the circuit components.
- Additional elements such as switches, fuses, and measuring instruments.

The three essential electrical quantities in a circuit are:
- Voltage (V): The electric force causing current flow, measured in volts (V).
- Current (I): The flow of moving charges needed for electrical devices to function, measured in amperes (A).
- Resistance (R): The opposition to current flow, measured in ohms (Ω).

Voltmeter: Measures voltage; must be connected in parallel to the load or supply.
Ammeter: Measures current; must be connected in series with the load.
Ohmmeter: Measures resistance; also connected in parallel, but power should be off during use.
Multimeter: Can measure voltage, current, and resistance; used for diagnosing electrical problems; can be analogue or digital.

Ensure the multimeter is configured correctly for measuring voltage, current, or resistance.
Voltage measurements require power to be on, while resistance measurements should be done with the power off to prevent electric shock.
Only trained personnel should perform voltage tests due to safety concerns.

Applies Ohm's Law: ( V = I \times R )
Calculate variables by rearranging the formula:
- Voltage (V): ( V = I \times R )
- Current (I): ( I = \frac{V}{R} )
- Resistance (R): ( R = \frac{V}{I} )
Example calculations illustrate application of Ohm's Law in practical scenarios.