Science - 2nd Feb

• Direct voltage causes electric current to flow in only one direction.
• The unit of measurement for voltage is volts (v)
• Voltage can be measured using a voltmeter
• A battery has two terminals, the positive (+) terminal and negative (-) terminal
• When no load is connected across the battery, there will not be any current flowing as there are no components that require energy.
• In a series circuit, all components are connected together with no branches
• In a parallel circuit, there are multiple paths that electricity can take
• Electrical circuits consist of three main parts; cells/batteries, wires and components such as bulbs, motors and switches.
• Series circuits have a single pathway for electricity to travel through
• Parallel circuits allow multiple devices to be powered from a single source
• In a series circuit, if one component fails or breaks down, it stops the flow of current through the entire circuit
• In a parallel circuit, if one component fails or breaks down, only that branch is affected and other components still work
• In a series circuit, the total resistance is equal to the sum of individual resistances
• The potential difference across a component can be calculated using Ohm's law (V=IR)
• The electrical resistance of a component in its opposition to a flow of charge. It is measures in ohms Ω
• • All the components in a circuit have some resistance
• The larger the resistance, the lower the current produced by a given voltage, but the higher the voltage required for a given current
• • If resistors are connected in series the total resistance with increase but, if resistors are connected in parallel, the total resistance with decrease as there are more paths for current to flow through