# Power - what is the use of calculating power and energy of signal?

1. Jul 6, 2012

### amaresh92

power -- what is the use of calculating power and energy of signal?

what is the use of calculating power and energy of signal?

2. Jul 6, 2012

### Staff: Mentor

Re: power

To see how far a signal can be transmitted given the medium of transmission.

3. Jul 6, 2012

### triden

Re: power

It gives you an idea of the magnitude of a signal relative to another signal. Say you drop 2 rocks with accelerometers on them, you can calculate the energy of the signals and then compare relative magnitudes to see which had more impact.

4. Jul 7, 2012

### sophiecentaur

Re: power -- what is the use of calculating power and energy of signal?

A general principle: Signals are used for communication of information. Everywhere, there is Noise (random fluctuations of electrical voltage / current). To transfer information, you need a margin of your wanted signal above the noise (and interference). Whilst you could always 'suck it and see' whether your information link will work or not, it makes good sense, always to calculate what signal level you expect to receive (and also the levels of interference and noise) first. You could same a lot of money this way.