Electric Current Flashcards
What is an electric current?
Electric current is the rate of flow of charge.
What does the cost of electricity depend on?
The cost of electricity depends upon the amount of electrical power used, the amount of time it is used for, and the charge made for each unit of electricity.
How is electric current measured?
It is measured with an ammeter and its units is ‘amps’ (A).
What does conventional current flow from?
Conventional current flows from the positive terminal of the power source to the negative terminal.
What is direct current?
Electrons travel in one direction only.
What is charge/electrical charge measured in?
Charge is measured in coulombs (c).
What is the equation to work out charge?
charge (c) = current (a) x time (s)
What is the equation for energy transferred?
energy transferred (joule, J) = potential difference (volt, V) × charge (coulomb, C)
What 2 things supply direct current?
Batteries and cells supply direct current.
What is an alternating current?
If the current constantly changes direction.
What is a voltmeter?
A voltmeter measures the potential different in volts across a component.
What is potential difference?
Potential different across a component is defined as the energy transferred per unit charge.
What is the equation for potential different?
Potential difference (volt, V) = energy (joule, J) divided by charge (coulomb, C)
