A-LEVEL Physics: 5.1.2 & 5.1.3: Current-Voltage Characteristics (Seneca)

Question 1

Ohmic Conductors always Obey…

Answer 1

Ohm’s Law.

Question 2

___ Conductors always Obey Ohm’s Law.

Answer 2

Ohmic.

Question 3

What does a ‘Current-Voltage Graph’ Show?

Answer 3

It shows how the Current & Voltage in a Circuit are Related.

Question 4

The Gradient of an I-V Graph is…

Answer 4

The Reciprocal of the Resistance in the Circuit.

Question 5

An Ohmic Conductor should have a ___ Relationship Between Current & Voltage. What type of I-V Graph does this produce?

Answer 5

Linear.
Straight-Line I-V Graph.

Question 6

At very High Voltages and Currents, the Linear Relationship between Current & Voltage breaks down. The Conductor is then…

Answer 6

Non-Ohmic.

Question 7

What is a ‘Diode’?

Answer 7

A Diode is an Electrical Component that Only Allows Current to Flow in One Direction (unless there are extreme conditions).

Question 8

A Diode will only let Current Flow in One Direction, Unless…

Answer 8

Unless the Voltage in the Other Direction is very Large.

Question 9

What is ‘Reverse Bias’?

Answer 9

Reverse Bias is the Direction in which the Current is Not Allowed to Flow by a Diode.

Question 10

What is Required for Current to Flow in Reverse Bias by a Diode?

Answer 10

A Very Large Voltage.

Question 11

The Voltage at which Current will Flow in Reverse Bias is Called the…

Answer 11

Breakdown Voltage.

Question 12

What is ‘Forward Bias’?

Answer 12

Forward Bias is the Direction that Current is Allowed to Flow by a Diode.

Question 13

The Point at which the Diode will Conduct Current in the Forward Direction is Called the…

Answer 13

Threshold Voltage.

Question 14

The Threshold Voltage of a Diode is Usually…

Answer 14

~0.6V

Question 15

The Filament Bulb is an example of a…

Answer 15

Non-Ohmic Conductor.

Question 16

Explain how a Filament Lamp is a Non-Ohmic Conductor: (3)

Answer 16

-The Current Flowing through the Filament Produces Heat.

-The Higher the Temperature of the Filament, the Higher the Resistance (as Electrons gain more KE, & obstruct more Current).’

-This Increase in Resistance Limits the Amount of Current that is Able to Flow through the Filament.

Question 17

For a Filament Bulb, an Increase in Voltage Supplied to the Bulb Does Not Produce the Same Increase in the ___ Flowing through.

Answer 17

Current.

Question 18

The I-V Graph for a Filament Bulb Displays a ___ ___ Relationship between the ___ & ___. Hence, the Graph is Not a ___ ___.

Answer 18

Non-Ohmic, Current & Voltage, Straight Line. (it is a ‘s’ shape through the origin).