To calculate the change in temperature, subtract the initial temperature from the final temperature. Example: 84.2 degree Fahrenheit - 41 degrees Fahrenheit = 43.2 degrees Fahrenheit. The temperature from morning to afternoon changed by 43.2 degrees Fahrenheit.
It needs 12 volts so it will be the standard modern power supply provides 12 volts of power.
Household Electricity. Cells and batteries provide an electrical current which always flows around the circuit in the same direct, this is called direct current (dc). In the UK mains electricity is supplied at about 230 volts and is supplied as (ac) or alternating current.