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

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


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.


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


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

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


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


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


Resistance increases with [ ]



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.


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


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

current that can flow


More current means an...

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


What is the formula for potential difference?

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


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

It is steady