Work of current is made by the electric field moving charges on the conductor and is an energy measure. The electric power is widely applied in life as it easily turns into other types of energy: light, chemical, mechanical, etc. To define work of current, it is necessary to know its force and tension.
Instruction
1. Electricity in many respects simplified life person, having made it more convenient and interesting. Now it is enough to click the switch and light will immediately be switched on, the washing machine will start working, the monitor of the computer or the screen of the TV, etc. will light up. For this purpose in each apartment electrical networks in which tension is supported by current sources are laid.
2. The source creates and maintains electric field, forcing to move on it electric charge. Work which at the same time is made is equal to the work of size of a charge on tension: A = q • U where A is work of current, q is electric charge, U is tension in W.
3. It is possible to define work of current in proportion to its force. So, the charge passes the site of a chain for some period equal to t. It is possible to find its size, having calculated the work of current on this parameter: q = I•t.
4. Substitute the received expression in a basic formula: A = U•I•t.
5. Unit of measure of work of current in the SI system is 1 Joule, by name the British physicist who removed connection of thermal energy with mechanical work. 1 Joule is equivalent to the energy unit created in the stationary electric field with a current of 1 Ampere of 1 W in 1 second of time.
6. There is also so-called stand-alone unit of work of current which is expressed in kW • h (kilowatt • hour). It is used when calculating the electric power in household and service premises and is specified in documents for payment of utilities. 1 kW • it is equal to 3,600,000 Joules or 3,600 kJ h.
7. The electric power is work of current which is made for a certain time interval and is spent by household appliances. That they consumed its minimum quantity and, therefore, saved the budget, it is necessary to pay upon purchase attention to other characteristic of current – power. This size is equal to the work of current made in unit of time.