Electrical Components Flashcards

All 6 cards in this deck

What is the shape of the current–potential difference graph for a fixed resistor at constant temperature?

A straight line through the origin — the resistance stays constant.

What is the shape of the current–potential difference graph for a filament lamp?

An S-shaped curve through the origin that gets shallower as current increases — resistance increases as the filament heats up.

What is the shape of the current–potential difference graph for a diode?

Almost no current until a small forward p.d., then current rises steeply; in reverse the resistance is very high and current is about zero.

How does the resistance of a light-dependent resistor (LDR) vary with light intensity?

Resistance decreases as light intensity increases (and is very high in the dark).

How does the resistance of an NTC thermistor vary with temperature?

Resistance decreases as temperature increases.

True or false? A filament lamp has a constant resistance whatever the current through it.

False. Its resistance increases as the current heats the filament, so its I–V graph is a curve.