Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as 47 Ω ± 10 % . Potential difference/ V Current / A 2.1 0.040 4.0 0.079 6.3 .0128 7.9 0.192 10.0 0.202 12.1 0.250 Plot a graph to show the I - V Characteristic of this resistor.

Carbon resistor with resistance R = 47 Ω ± 10 % Given by the manufacturer. I - V characteristic of the resistor according to the results of the experiment is drawn below. From Ohm's law we have V = I R . So, we get an equation of straight line passing through the origin, so the graph should pass through origin.

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as 47 Ω ± 10 % . Potential difference/ V Current / A 2.1 0.040 4.0 0.079 6.3 .0128 7.9 0.192 10.0 0.202 12.1 0.250 Plot a graph to show the I - V Characteristic of this resistor.

Carbon resistor with resistance R = 47 Ω ± 10 % Given by the manufacturer. I - V characteristic of the resistor according to the results of the experiment is drawn below. From Ohm's law we have V = I R . So, we get an equation of straight line passing through the origin, so the graph should pass through origin.

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as 47 Ω ± 10 % . Potential difference/ V Current / A 2.1 0.040 4.0 0.079 6.3 .0128 7.9 0.192 10.0 0.202 12.1 0.250 Do the points appear to fall on a straight line that passes through the origin of the graph?

Yes, the points appear to fall on a straight line that passes through the origin of the graph except 7 . 9 . Since this point is anomalous and can be ignored.So we can say Yes all the points appear to fall on a straight line passing through origin.We all know that Ohm's law indicates that the line will pass through the origin. V = I R .

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as 47 Ω ± 10 % . Potential difference/ V Current / A 2.1 0.040 4.0 0.079 6.3 .0128 7.9 0.192 10.0 0.202 12.1 0.250 Use the graph to determine the resistance of the resistor.

Using the above graph we need to calculate the resistance of the resistor. Which can be written as change in X coordinate, i.e, change in the voltage upon change in Y coordinate ,i.e, change in the current. So, R = ∆ V ∆ I = 12 - 0 0 . 25 - 0 = 48 Ω ∴ The required resistance R of the resistor is 48 Ω .

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as 47 Ω ± 10 % . Potential difference/ V Current / A 2.1 0.040 4.0 0.079 6.3 .0128 7.9 0.192 10.0 0.202 12.1 0.250 Does the value of the resistance fall within the range given by the manufacturer?

Yes, the resistance fall in the range given by the resistor. The range of the manufacturer is 47 Ω ± 10 % Which implies that the range is 47 - 4 . 7 = 42 . 3 Ω to 47 + 4 . 7 = 51 . 7 Ω And since the value of resistance came out to be R = ∆ V ∆ I = 12 - 0 0 . 25 - 0 = 48 Ω ∴ The required resistance R of the resistor is 48 Ω .

EASY

AS and A Level

IMPORTANT

Earn 100

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as $47 Ω \pm 10 %$ .

Potential difference/ V Current / A

2.1 0.040

4.0 0.079

6.3 .0128

7.9 0.192

10.0 0.202

12.1 0.250

Plot a graph to show the $I - V$ Characteristic of this resistor.

Important Questions on Resistance and Resistivity

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 10 - Resistance and Resistivity>Question>Q 1

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as

$47 Ω \pm 10 %$ .

Potential difference/ V	Current / A
2.1	0.040
4.0	0.079
6.3	.0128
7.9	0.192
10.0	0.202
12.1	0.250

Do the points appear to fall on a straight line that passes through the origin of the graph?

MEDIUM

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 10 - Resistance and Resistivity>Question>Q 1

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as $47 Ω \pm 10 %$ .

Potential difference/ V	Current / A
2.1	0.040
4.0	0.079
6.3	.0128
7.9	0.192
10.0	0.202
12.1	0.250

Use the graph to determine the resistance of the resistor.

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 10 - Resistance and Resistivity>Question>Q 1

Table shows the results of an experiment to measure the resistance of a carbon resistor whose resistance is given by the manufacturer as $47 Ω \pm 10 %$ .

Potential difference/ V	Current / A
2.1	0.040
4.0	0.079
6.3	.0128
7.9	0.192
10.0	0.202
12.1	0.250

Does the value of the resistance fall within the range given by the manufacturer?

EASY

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 10 - Resistance and Resistivity>Question>Q 2

An electrical component allows a current of $10 m A$ through it when a voltage of $2.0 V$ is applied. When the voltage is increased to $8.0 V$ , the current becomes $60 m A$ . Does the component obey Ohm’s law? Give numerical values for the resistance to justify your answer.