Αποτελέσματα Αναζήτησης
By the end of this section, you will be able to: Express electrical power in terms of the voltage and the current. Describe the power dissipated by a resistor in an electric circuit. Calculate the energy efficiency and cost effectiveness of appliances and equipment.
Electrical energy is popular because it is so easily transmitted from one place to another, and converted into other forms of energy. The concepts and principles of electricity are beautiful and intricate, but this is hardly the place to present them in complete detail.
Power is measured in Watts, W Energy is measured in Joules, J Time is measured in seconds, s. so combining these equations we get a new. Q. one to calculate the energy in an electric circuit:
Electric power (\(P\)) is simply the product of current times voltage. Power has familiar units of watts. Since the SI unit for potential energy (PE) is the joule, power has units of joules per second, or watts. Thus, \(1 A \cdot V = 1 W\).
The electrical energy (E) used can be reduced either by reducing the time of use or by reducing the power consumption of that appliance or fixture. This not only reduces the cost but also results in a reduced impact on the environment.
In this experiment we will measure the Joule constant by converting electrical energy to heat. The calorie is defined as the amount of heat energy required to raise the temperature of one gram of liquid water one Celsius degree. This amount of heat is nearly independent of the initial temperature.
Energy, measured in joules (J), is transferred from chemical energy in the battery to electrical energy used by circuit components and then to the surroundings. The power of a component is measured in watts (W) and is given by P=IV (by using V=IR, this can be shown to be equivalent to P=I2R and P=V2/R).
