Circuit Components And Current-Voltage Graphs Flashcards
To learn about circuit components and the characteristics of various graphs
What is the resistance when:
Potential difference=230V
Current=7A
32.9 Ohms
Why does a diode need a resistor placed in series?
To prevent a high current from damaging it
What pattern is shown by the graph of a filament graph?
As the voltage increased, the current increased at a slowing rate
What pattern is shown by the graph of a diode?
As voltage increases, the current increased at an increasing rate
In a metal there are ____________ electrons that can move through the material when connected to a voltage. The _______ electrons move between the _________ ions that make up the rest of the metal
Delocalised
Free
Positive
The resistance will be affected by the ____________ and ______________ of the positive metal ions.
Spacing
Vibration
What are the 4 factors that affect the resistance of a wire?
Material
Length
Cross-sectional area
Temperature
What are current voltage graphs also known as?
I-V graphs
In I-V graphs, we plot current on the ___-axis and voltage on the ___-axis.
Y
X
How are current-voltage graphs useful?
They are useful for comparing the behaviour of circuit components
If a graph is a straight line through the origin, the resistance is the _________ of the ___________.
If not, resistance is found for a point on a line by finding the _________ reading and dividing it by the _________ reading.
Inverse
Gradient
Voltage
Current
An LED allows current to flow any direction
True or False?
False
A hot wire has _________ resistance as it is __________ for electrons to pass through it
Greater
Harder
Filament lamp allows current to flow in both directions
True or False?
True
What are the advantages of LED’s?
Long lifetime
More robust
Switch on quickly
More efficient
In series, the current is the _______ at all points
Same
In series, the voltage provided is equal to the ______ of the voltages of the components
Sum
In parallel, each branch receives the _____ voltage
Same
In parallel, the ____ of the current in the branches __________ the total current
Sum
Equals
V = ?
I x R
Diodes have very ______ resistance in the ___________ direction to which it was intended
High
Reverse
If a graph is a _________ line through the origin, the ____________ is the inverse of the ____________
Straight
Resistance
Gradient
To find resistance for a point on a line, we do:
___________ reading
Current
For a fixed resistor, the current is directly proportional to the …?
This relationship also applies if the flow of electricity is …?
Voltage
Reversed
How do filament lamps produce light?
As the ___________ increases, the lamp gets hot
The hit wire has ________ resistance as it is __________ for the electrons to pass through it
By heating up a filament tungsten
Current
Greater
Harder
Filament lamps allow current to flow in one direction.
True or False?
False
They allow current to flow in both directions
LEDs allow current to flow in one direction
True or False?
In the reverse direction, the current is very _____. In this direction the resistance is very __________
True
Low
Large
Why can current only flow one way through a diode?
They contain semi-conductors which only allow current to flow through one way
R = R + R +…
______ 1 2
Total
The total resistance in series is the sum of …?
The individual resistances
