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Flashcards in Resistance and V=IR Deck (13):
1

Describe the relationship between the current through a resistor and the potential difference

The current through a resistor (at a constant temp) is directly proportional to P.D

2

Describe the graph for different resistors (V = x-axis, I = y-axis)

Straight, positive lines through the origin. Different slopes on different lines because different resistors have different resistances.

3

Describe the graph for a filament lamp (V = x-axis, I = y-axis)

Like a sin graph from sin(-90) to sin(90)
Page 102

4

Describe the relationship between a filament lamp (temperature) and resistance

As the temp. of the filament increases, the resistance increases

5

Describe current and resistance in a diode

Current will only flow in 1 direction through a diode. The diode has a very high resistance in the opposite direction

6

Describe the graph for a filament lamp (V = x-axis, I = y-axis)

Flat line of y=0 until the origin where it increases in a positive curve, steeper than exponentially
Page 102

7

Resistance increases with [ ]

Temperature

8

What happens when an electrical charge flows through a resistor? (Energy)

Some of the electrical energy is transferred to heat energy and the resistor gets hot. The heat causes the ions in the conductor to vibrate more.

9

Why does resistance increase as temp. increases?

The heat (of the resistor) causes the ions in the conductor to vibrate more. This makes it more difficult for the charge-carrying electrons to get through the resistor - the current can't flow as easily and the resistance increases

10

For most resistors there's a limit to the amount of [ ]

current that can flow

11

More current means an...

Increase in temperature, which means an increase i resistance, which means the current decreases again

12

What is the formula for potential difference?

P.D = Current * Resistance
V = IR
Current = Amps, A
P.D = Volts, V
Resistance = Ohms, Ω

13

What does a straight line graph tell you about the resistance?

It is steady