8TH GRADE · WORK AND CURRENT POWER
Operation, power and energy consumption
Electrical work, appliance power and household energy metering.
The entire theory of the lesson is collected here; you can read it without an account. In interactive mode, the same theory appears as cards, followed by questions. with checking the answer and task, and progress is saved.
Basic Concepts
Work of electric current
Energy transferred by an electric field to charges and converted by the device into other forms.
At constant voltage and current, work is equal to their product times time.
Electric current power
The work done by electric current per unit of time, showing the rate of energy consumption.
The power on the device plate helps to estimate the current, energy consumption and permissible network load.
Electrical energy metering
A household meter measures the work done by a current, usually expressed in kilowatt-hours.
One kilowatt-hour is equal to the energy of a one-kilowatt device operating for one hour.
Physical quantities
Current work
Electrical energy converted by the device during operation.
Unit: joule ·
Electrical power
Work done by electric current per unit time.
Unit: watt ·
Device operating time
Duration of electrical energy consumption by the device.
Unit: second ·
Lesson formulas
Work of electric current
The work done by current is equal to the product of voltage, current and time.
Electric current power
Electrical power is equal to voltage times current.
Related formulas
The same formulas in the reference, with symbols and units.
Tasks on the topic
Statements, answer options and the walkthrough.