Brief Summary
This video explains the two types of electrical current: alternating current (AC) and direct current (DC). AC involves a current that constantly changes direction, while DC involves a current that flows in one direction only. The video also mentions that UK mains electricity is AC at 50 Hz and around 240 volts, and that oscilloscopes are used to visualise potential difference over time.
- Alternating Current (AC) vs. Direct Current (DC)
- UK Mains Electricity Specifications
- Use of Oscilloscopes
Alternating Current (AC)
Alternating current (AC) is characterised by the constant swapping of the current's direction. This means the charge flows in one direction, then the opposite direction, repeatedly. AC is generated by an alternating potential difference, or voltage, which fluctuates between positive and negative values. When graphed, the potential difference or current over time shows constant fluctuation between negative and positive values, reflecting the changing direction of charge flow.
UK Mains Supply
In the UK, mains electricity, which powers devices via plug sockets, is AC. Specifically, UK mains supply operates at 50 Hertz and around 240 volts. This means the potential difference fluctuates from positive 240 volts to negative 240 volts and back 50 times per second, with the current fluctuating at the same rate. The voltage can also be referred to as 230 volts, and both 230V and 240V are considered correct.
Direct Current (DC)
Direct current (DC) is produced by a direct potential difference, which remains either positive or negative. Consequently, the charge always flows in the same direction. DC is commonly found in devices powered by cells and batteries, such as phones and calculators.
Oscilloscopes
Oscilloscopes are devices used to obtain potential difference versus time graphs. These instruments display the graphs on a monitor, allowing for the visualisation of current and voltage fluctuations.
