Physics Circuit Symbols Flashcards
What does a cell provide to a circuit?
Electrical energy
The longer line on a cell symbol indicates the positive side.
How is a battery defined?
A battery consists of two or more cells
A battery provides electrical energy to a circuit.
What happens when current flows through a lamp?
It converts electrical energy to light energy
A lamp lights up when current is present.
What is the function of a switch in a circuit?
It allows you to complete or break a circuit
A switch allows current to flow when closed.
Fill in the blank: A cell shows the _______ side with a longer line.
Positive
Fill in the blank: A battery provides _______ energy to a circuit.
Electrical
True or False: A lamp lights up only when there is no current flowing through it.
False
True or False: A switch can either allow or prevent current in a circuit.
True
What is a resistor?
A resistor restricts the flow of current, which may be to protect other components.
What is a variable resistor?
A variable resistor is a resistor whose resistance can be varied in the circuit.
It could be used as a dimmer switch.
What does a voltmeter measure?
A voltmeter measures potential difference.
It must be placed in parallel to measure the difference in electrical potential between two points.
What does an ammeter measure?
An ammeter measures current.
Must be placed in series to measure current flowing in a circuit.
What is a LED?
A LED emits light when a current flows but only allows current to flow in one direction.
Requires less energy than a lamp.
What does a motor do?
A motor converts electrical energy into kinetic energy by turning.
What is the function of a microphone?
A microphone generates a voltage when sound reaches it. It converts sound energy into an electrical signal.
It is used in a telephone or an intercom.
What does a loudspeaker do?
Converts electrical energy into sound energy.
What is a photovoltaic cell?
Converts light energy to electrical energy, can be used as the power source in a circuit. More light will mean a greater p.d. across the cell.
What is the purpose of a fuse?
A fuse is a safety device - the metal core will melt when too much current is flowing in the circuit.
What does a diode do?
A diode allows current to flow through it in one direction only.
What is a capacitor?
A device that stores electrical charge and can be used in timing circuits or in the flash of a camera.
What happens to the resistance of a thermistor as temperature increases?
The resistance of a thermistor increases as the temperature increases.
What is an LDR used for?
An LDR can be used to control a circuit; its resistance decreases as light increases.
What is a relay?
An electronically operated switch used to protect operators from high currents by using a low current supply to switch on a high current/voltage supply.
What is an NPN Transistor?
Acts as a switch when a voltage of 0.7 V is applied across the base and emitter.
What is an N-Channel enhancement MOSFET Transistor?
Acts as a switch when a voltage of approximately 2 V is applied across the gate and the source.
