Circuit Components And Current-Voltage Graphs

Question 1

What is the resistance when:
Potential difference=230V
Current=7A

Answer 1

32.9 Ohms

Question 2

Why does a diode need a resistor placed in series?

Answer 2

To prevent a high current from damaging it

Question 3

What pattern is shown by the graph of a filament graph?

Answer 3

As the voltage increased, the current increased at a slowing rate

Question 4

What pattern is shown by the graph of a diode?

Answer 4

As voltage increases, the current increased at an increasing rate

Question 5

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

Answer 5

Delocalised
Free
Positive

Question 6

The resistance will be affected by the ____________ and ______________ of the positive metal ions.

Answer 6

Spacing

Vibration

Question 7

What are the 4 factors that affect the resistance of a wire?

Answer 7

Material
Length
Cross-sectional area
Temperature

Question 8

What are current voltage graphs also known as?

Answer 8

I-V graphs

Question 9

In I-V graphs, we plot current on the ___-axis and voltage on the ___-axis.

Answer 9

Y

X

Question 10

How are current-voltage graphs useful?

Answer 10

They are useful for comparing the behaviour of circuit components

Question 11

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.

Answer 11

Inverse
Gradient
Voltage
Current

Question 12

An LED allows current to flow any direction

True or False?

Answer 12

False

Question 13

A hot wire has _________ resistance as it is __________ for electrons to pass through it

Answer 13

Greater

Harder

Question 14

Filament lamp allows current to flow in both directions

True or False?

Answer 14

True

Question 15

What are the advantages of LED’s?

Answer 15

Long lifetime
More robust
Switch on quickly
More efficient

Question 16

In series, the current is the _______ at all points

Answer 16

Same

Question 17

In series, the voltage provided is equal to the ______ of the voltages of the components

Answer 17

Sum

Question 18

In parallel, each branch receives the _____ voltage

Answer 18

Same

Question 19

In parallel, the ____ of the current in the branches __________ the total current

Answer 19

Sum

Equals

Question 20

V = ?

Answer 20

I x R

Question 21

Diodes have very ______ resistance in the ___________ direction to which it was intended

Answer 21

High

Reverse

Question 22

If a graph is a _________ line through the origin, the ____________ is the inverse of the ____________

Answer 22

Straight
Resistance
Gradient

Question 23

To find resistance for a point on a line, we do:

___________ reading

Answer 23

Current

Question 24

For a fixed resistor, the current is directly proportional to the …?

This relationship also applies if the flow of electricity is …?

Answer 24

Voltage

Reversed

Question 25

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

Answer 25

By heating up a filament tungsten Current Greater Harder

Question 26

Filament lamps allow current to flow in one direction. True or False?

Answer 26

False They allow current to flow in both directions

Question 27

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 __________

Answer 27

True Low Large

Question 28

Why can current only flow one way through a diode?

Answer 28

They contain semi-conductors which only allow current to flow through one way

Question 29

R = R + R +… | ______ 1 2

Answer 29

Total

Question 30

The total resistance in series is the sum of ...?

Answer 30

The individual resistances