4.1 Current And Charge Flashcards
What is electrical current?
A flow of charge
Electrical current involves the movement of charged particles, primarily electrons.
What happens when an electric torch is turned on?
Millions of electrons pass through the bulb and the cell every second
This demonstrates the flow of electrical current in a practical application.
What charge does each electron carry?
A negative charge
Electrons are fundamental particles that contribute to electric charge.
What characteristic of metals allows for the flow of electric current?
Metals contain lots of electrons that move freely between positively charged metal ions
This property of metals is crucial for their conductivity.
How do electrons affect the movement of metal ions?
Electrons stop the ions from moving away from each other
This interaction helps maintain the structure of the metal while allowing current to flow.
What defines the size of an electric current?
The rate of flow of electric charge
This is usually measured in amperes (A).
What is the relationship between the number of electrons and the current?
The bigger the number of electrons that pass through a component each second, the bigger the current
This illustrates how current is directly proportional to electron flow.
Whats the cells function?
A cell is necessary to push electrons around a complete circuit. A battery consists of two or more cells. The + symbol next to the long line of the cell indicates that this is the positive terminal of the cell.
What does the switch allow you to do?
A switch enables the current in a circuit to be switched on or off.
What is an indicator designed to do?
An indicator, such as a bulb, is designed to emit light as a signal when a current passes through it.
What does the diode do?
A diode allows current through in one direction only.
What happens when a current passes through a light emitting diode (LED)
A light-emitting diode (LED) emits light when a current passes through it.
What does an ammeter measure?
An ammeter is used to measure electric current.
What is the purpose of a fixed resistor?
A fixed resistor limits the current in a circuit.
What does the variable resistor do?
A variable resistor allows the current to be varied.
