P2a Electrical Circuits

What is the circuit symbol for a bulb?

Circle with a cross

What is the circuit symbol for a cell?

Two lines, one shorter than the other

What is the circuit symbol for a battery?

Two lines, one shorter than the other, repeated at least twice

What is the circuit symbol for an ammeter?

Circle with an A

What is the circuit symbol for a voltmeter?

Circle with a V

What is the circuit symbol for a switch?

A break in the wire line

What is the circuit symbol for a fuse?

Rectangle with a line through

What is the circuit symbol for a diode?

Circle with an arrow and line inside

What is the circuit symbol for a LED?

Circle with an arrow and line inside and two arrows pointing out

What is the circuit symbol for a resistor?

Rectangle

What is the circuit symbol for a variable resistor?

Rectangle with an arrow through

What is the circuit symbol for a thermistor?

Rectangle with a bent line through

What is the circuit symbol for an LDR?

Rectangle with a circle around and two arrows pointing in

What is the function of an electrical cell?

Provides energy to the electrons, or provides potential difference

What is the function of a battery?

Provides energy to the electrons, or provides potential difference

What is the function of a fuse?

Breaks and stops the circuit if the current is too high

What is the function of a switch?

Breaks or completes the circuit

What is the function of a bulb?

transfers energy as radiation (light)

What is the function of a diode?

Breaks and stops the circuit if the current is too high

What is the function of an LED?

Allows current to only flow in one direction

What is the function of a resistor?

Increases the resistance of a circuit

What is the function of a variable resistor?

Increases the resistance of a circuit, and can be changed

What charge do electrons have?

Negative

What equation links current, charge flow & time?

charge flow = current × time

What is the unit for charge flow?

Coulombs (C)

What is the unit for current?

Amps (A)

What is the unit for time?

Seconds (s)

What happens to current flow if the resistance increases?

Decreases

What equation links current, resistance & potential difference?

potential difference = current × resistance

What is the unit for potential difference?

Volts (V)

What is the unit for resistance?

Ohms (Ω)

What is the function of an ammeter?

Measures the current in a circuit

What is the function of a voltmeter?

Measures the potential difference through a component

Where should an ammeter be placed in a circuit?

In series with the components

Where should a voltmeter be placed in a circuit?

On a parallel bridge around the component of interest

What does 'components in series' mean?

The same electrons flow through components in series

What does 'components in parallel' mean?

The same electrons cannot flow through components in parallel, because they are on different branches of a circuit

What happens to current through components connected in series?

there is the same current through each component

What happens to the total resistance of components connected in series?

the total resistance of two components is the sum of the resistance of each component

What happens to the potential difference across components connected in series?

the total potential difference of the power supply is shared between the components

What happens to current through components connected in parallel?

the current splits across the components (the total current through the whole circuit is the sum of the currents through the separate components)

What happens to the total resistance of components connected in parallel?

the total resistance of two resistors is less than the resistance of the smallest individual resistor

What happens to the potential difference across components connected in parallel?

the potential difference across each component is the same

What is the unit for power?

Watts, or W

What does the amount of energy an appliance transfers depend on?

how long the appliance is switched on for and the power of the appliance

What equation links power, energy transferred, and time?

energy transferred = power × time

What is the unit for energy transferred?

Joules, or J

What is the unit for work done?

Joules, or J

What is the definition of a circuit?

a power supply connected to a complete loop of wires and components

What is the definition of components in series?

components arranged so that electrons flow through both of them before completing the circuit

What is the definition of components in parallel?

components arranged so that electrons flow only one or the other before completing the circuit

What is the definition of a component?

something in an electrical circuit, like a bulb or battery

What is the definition of charge?

a property of particles; they can be positive, negative, or neutral

What is the definition of current?

how much charge (electrons) flows each second

What is the definition of potential difference?

how much energy is transferred to or from the charges (electrons) as they pass through a component

What is the definition of resistance?

how much the component resists the flow of charge

What is the definition of electrical power?

how much energy is transferred each second