What Is the Difference Between These Electrical Power Equations?

[AznBoi]

Can someone please explain the difference between these three equations? I'm having trouble understanding their meanings and have no idea when I should use each one. Thanks.

P= I \Delta V

P= I^{2}R = \frac{\Delta V^{2}} {R}

 

[mjsd]

they all gives you power P. depending of the situation, you may be given or could work out only two of them and not all. for instance, if you know a battery is pumping 0.3A into a circuit and across its terminal it is 3V then power the battery is providing is P=VI=0.3x3=0.9W. for another instance, you may want to calculate power dissipated at a load of resistance R, then if you know the current through it, you can work out P=I^2 R.