I-V Characteristics

Question 1

What’s the ideal voltmeter?

Answer 1

• Assumed to have an infinite resistance (so no current flows through them)

Question 2

What’s the ideal ammeter?

Answer 2

• Assumed to have no resistance (so will have no potential difference across it)

Question 3

Why does the IV graph for a filament lamp level off at high currents?

Answer 3

High current means an increase in temperature, which increases resistance which decreases current

Question 4

What are diodes made from?

Answer 4

Semiconductors

Question 5

What is forward bias?

Answer 5

The direction that current is allowed to flow

Question 6

What’s the threshold voltage?

Answer 6

• The voltage required in the forward direction before the diode starts to conduct electricity
• 0.6V

Question 7

What’s reverse bias?

Answer 7

The resistance of the diode is very high in the other direction so little current can flow