Energy and Power Basic

in general we are checking whether the signal is power signal or energy signal. What is the use of finding whether the signal is power or energy signal. Do we have any special characteristics for energy and power signal that will be usefull for further analyses.In a nutshell WHY DO WE WANT CARE THE SIGNAL IS POWER OR ENERGY .Thank you in advance

I suggest that you learn the difference between Energy and Power.

Try Wikipedia.

ya i have learnt,now could you say me whether the step signal is power signal or energy signal with explanation ?

Hi Nick,

Signal Fundamentals


An energy signal has a finite energy. Signals of a limited length also carry a finite energy, and so they are energy signals. A signal that decays exponentially can be another example.

A power signal is not limited in time and has an infinite energy. Since an infinite energy has no meaning for us, then we use the energy per unit of time,which is power.

For example, if x(t) represents the potential (in volts) of an electrical signal propagating across a transmission line, then Z would represent the characteristic impedance (in ohms) of the transmission line. The units of measure for the signal energy E(s) would appear as volt2·seconds, which is not dimensionally correct for energy in the sense of the physical sciences. After dividing E(s) by Z, however, the dimensions of E would become volt2·seconds per ohm, which is equivalent to joules, the SI unit for energy as defined in the physical sciences. - (Wikipedia)

I hope this helps,
Kevin

Energy is what makes change happen and can be transferred form one object to another. Energy can also be transformed from one form to another.
Power is the rate at which energy is transferred. It is not energy but is often confused with energy. The watt is the most commonly used unit of measure for power. It measures the rate of energy transfer.
A watt equals a joule per second. If a smart phone uses five joules of energy every second, then the power of the phone is five joules per second, or five watts.

yes absolutly right...

There are different forms of energy. These include kinetic, potential, thermal, gravitational, electromagnetic, sound, light and elastic. The form of energy is dependent on the frame of reference, and can be transformed into other forms. For instance potential energy is dependent on the position of the object, whereas kinetic energy is the energy required to accelerate an object to a particular speed, and so on.

Different forms of power could be electric power, which is the rate at which electrical energy is transferred by a circuit, human power, and optical power.