Physics 5.1.1-2 Basics of Electricity and Current-Voltage Characteristics

17 flashcards · Physics · by TheoTyson

1. What is conventional current flow?

   From positive to negative.

2. What is electron flow?

   From negative to positive.

3. What is current?

   The rate of flow of charge.

4. How do you attach an ammeter?

   In series so that the current is the same as in the circuit, with an ideal zero resistance.

5. What is potential difference?

   The work done per unit charge.

6. How do you attach a voltmeter?

   In parallel so that the pd is the same as in the circuit, with an ideal infinite resistance so no current flows.

7. What is resistance?

   A measure of how difficult it is to get current to flow through it.

8. What is Ohm's law?

   The current through an ohmic conductor is directly proportional to the potential difference.

9. When is Ohm's law true?

   Under constant physical conditions and the component is an ohmic conductor.

10. What is the current-voltage\text{current-voltage}current-voltage graph for an ohmic conductor?

11. What is the current-voltage\text{current-voltage}current-voltage graph for a filament lamp?

12. What is the current-voltage\text{current-voltage}current-voltage graph for a semiconductor diode?

13. What is the gradient of voltage-current\text{voltage-current}voltage-current /\text{/}/ V-I\text{V-I}V-I graph?

    The resistance of the component at that point.

14. How does the resistance of a metal change as the temperature changes?

    As temperature increases, the resistance of the metal increases.

15. What is forward bias in a diode?

    The direction in which the current is allowed to flow.

16. What is reverse bias in a diode?

    The resistance is very high, so only a very small amount of current can flow.

17. What is the threshold voltage?

    The voltage before forward bias happens, typically around 0.6V.