A positive connection is one in which a change (increase or decrease) in some variable results in the same type of change (increase or decrease)in a second variable. The positive connection in the figure below for a cooling coffee cup implies that the hotter the coffee is the faster it cools.
The power consumption of small devices is usually measured in Watts, and the power consumption of larger devices is measured in kilowatts (kW), or 1,000 Watts. Electricity generation capacity is often measured in multiples of kilowatts, such as megawatts (MW) and gigawatts (GW).
What is a unit of electricity. Your electricity bill will show the electricity used in 'units', the price of each unit is also shown. Ever wondered what a 'unit' of electricity is or how long you can run an appliance for on one unit. The examples below will help you to understand just what a unit is and just how much it buys you in real terms! One unit of electricity is exactly equal to 1000 Watts of power used for 1 hour. Look at the cost you pay per unit (unit cost) (this may be anywhere between 4p and 12p depending upon your supplier and any special discount schemes) you can get the exact amount per unit from your electricity bill.