4.1 Current And Charge Flashcards
What is the purpose of a cell in an electric circuit?
A cell is necessary to push electrons around a complete circuit, giving energy to drive the current.
What is the symbol for a cell in a circuit diagram?
A short line and a long line, with the long line showing that it’s the positive terminal.
Define electric current.
Electric current is the flow of charge, specifically the flow of electrons through a conductor
What unit is used to measure electric current?
The ampere (A), or simply “amp.”
What does a switch do in a circuit?
A switch allows current to be turned on or off in a circuit.
What component emits light when current passes through it?
What component emits light when current passes through it?
What is the function of a fuse in a circuit?
A fuse is designed to melt and break the circuit if the current gets too high, protecting the circuit from damage.
What equation represents the relationship between charge flow, current, and time?
Q
I
×
t
Q=I×t, where
Q
Q is charge flow in coulombs,
I
I is current in amperes, and
t
t is time in seconds
What is the role of a variable resistor?
A variable resistor allows the current in a circuit to be adjusted or varied.
How is electric charge measured?
Electric charge is measured in coulombs (C).
What does a diode do in a circuit?
A diode allows current to flow in one direction only, preventing reverse current
What does a voltmeter measure in a circuit?
A voltmeter measures the potential difference (voltage) across components in a circuit.
What happens to the torch bulb in Figure 4 when the slider of the variable resistor is moved back?
The bulb dims as the amount of current through it decreases.
Describe the purpose of an ammeter in a circuit.
An ammeter measures the electric current flowing through a circuit.
What is the difference between a battery and a cell?
A cell is a single unit that provides electrical energy, while a battery consists of two or more cells connected together.
