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.
Volts, Amps, and Watts of Christmas Lights In the US, the standard power from an outlet is 120 volts. Traditionally, a string of 48 mini-bulbs uses 2.5 volts. 48 times 2.5 equals 120, and so it logically follows that a single strand will equal the standard number of volts from an outlet.