# Separate Physics - 6.2 Flashcards

What are the circuit symbols for a switch (open and closed), a cell and a battery?

What are the circuit symbols for a diode, resistor, variable resistor and LED?

What are the circuit symbols for a lamp, fuse and voltmeter?

What are the circuit symbols for an ammeter, thermistor and LDR?

For electrical charge to flow through a closed circuit what must be included?

A source of potential difference

What is electrical current and what determines the size of the current?

The flow of electrical charge, determined by the rate of flow

What is the equation for charge flow?

In a single closed loop, what value would the current have at any point?

The same value

What affects the current through a given component?

The resistance of the component and the potential difference across it

For a given potential difference, what happens to the current when the resistance increases?

The current gets smaller

What equation links potential difference, current and voltage?

What happens to the resistance of an ohmic conductor (such as a wire) when the current changes?

The resistance of ohmic conductors doesn’t change with current

What happens to the resistance of a diode or filament lamp when current changes?

Resistance increases with temperature, such as the current increases the resistance increases

Draw and describe an I-V graph for an ohmic resistor (e.g. a resistor at a constant temperature)

Current (at constant temperature) is directly proportional to potential difference

Draw and describe an I-V graph for a filament lamp

As the current increases the temperature of the filament lamp increases (so the resistance increases) meaning less current can flow per unit potential difference