Power & Energy

Power and energy calculations also are important in circuit analysis. One reason is that although voltage and current are useful variables in the analysis and design of electrically based systems, the useful output of the system often is nonelectrical, and this output is conveniently expressed in terms of power or energy.


More Explanation


The word “energy” is used to describe many different things—how we heat and cool our homes, how we fuel cars, and even how we’re feeling on a day. Energy isn’t something that can be seen or felt, but you can see and feel the effects when energy is transferred from one place to another. Energy is what makes change happen and can be transferred from 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.


Some of the different forms of energy include: elastic, light, sound, electromagnetic, gravitational, thermal, potential and kinetic energy. The most widely known form of power is electrical power, which is the rate at which electrical energy is transmitted by a closed circuit. Other forms of power may include optical power and human power. Energy can be converted from one form into another. For example, a battery produces electrical energy after converting it form chemical energy. The process of chemical explosion converts chemical energy into thermal and kinetic energy. Power cannot be transformed or converted. Since power is an instantaneous quantity, it cannot be stored. Energy is available in a time component and can therefore be stored for future use. Levers reduce the amount of energy required to accomplish tasks, but they are typically described by their power rating. Powerful levers are more efficient​