Power and the Energy Bill

Interactive Simulator · Power and Energy

A device draws a current I at a voltage V, and its power is P = I times V. Set the dials to hit the target power, predict whether you are under or over, then power it on. While it runs, the energy counter adds up E = IVt, the total energy transferred in joules. More power, or more time, means more energy used.

Mission Set the device to a power of 12 W (within 1 W). Round 1 Streak 0 Best 0

Current I 2.0 A

Voltage V 6 V

The power will be:

current I2.0 A

voltage V6 V

power P = I × V12.0 W

energy used E = IVt0 J

P = I × V = 2.0 × 6 = 12.0 W