quiz 10 Flashcards
Why are variable resistors used in circuits to measure I-V characteristics of components?
To vary the current and potential difference of the component
Why are filament lamps and diodes not ohmic conductors?
Their resistance changes as current changes
Is a wire at a constant temperature an ohmic conductor?
Yes
State another name for an ohmic conductor
Linear
State the name for a non-ohmic conductor.
Non-linear
State the relationship between current and potential difference for an ohmic conductor
Current is directly proportional to potential difference at constant temperature
What do we call graphs which show the relationship between current and potential difference for a component
I-V plots
How does the resistance of a filament lamp change as the potential difference across it increases?
Current increases,so temperature increases, so resistance increases
Why does the resistance of a filament lamp increase as current increases?
The temperature of the filament increases causing ions to vibrate more
Is a diode an ohmic conductor?
No
Is a fixed resistor at a constant temperature an ohmic conductor?
Yes
State an example of an ohmic conductor?
A wire or fixed resistor
State the properties of a diode?
current only flows through a diode in one direction
Is a filament lamp an ohmic conductor?
No
Why are wires and resistors ohmic conductors?
Their resistance stays constant as current changes
