2.1 Current, potential difference and resistance

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Question 30

An electronics technician investigated how the total resistance of identical precision resistors connected in series varied with the number of resistors. The technician used a high-precision digital multimeter to measure the total resistance of the resistors. Table 1 shows the technician's results for 5 resistors in series.

Table 1

Number of resistors	Reading 1 ( $Ω\Omega$ )	Reading 2 ( $Ω\Omega$ )	Reading 3 ( $Ω\Omega$ )	Mean ( $Ω\Omega$ )
5	219.95	220.05	220.00	220.00

Calculate the mean resistance of 1 resistor.

[2]

What was the resolution of the multimeter the technician used?

0.01 Ω
0.05 Ω
0.10 Ω
220.00 Ω

[1]

How do the results show that the technician's measurements were precise?

The measurements are accurate.
The measurements are grouped closely together.
The measurements are reproducible.

[1]

How would a graph of mean total resistance against the number of resistors show that the total resistance is directly proportional to the number of resistors?

The results give a line with a positive gradient starting from the y-axis.
The results give a straight line that would go through the origin.
The results show a linear relationship with a non-zero intercept.

[1]

Predict the mean total resistance of 12 of these resistors connected in series.

[2]

2.1 Current, potential difference and resistance

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Question 30

Table 1

Number of resistors	Reading 1 ( $Ω\Omega$ )	Reading 2 ( $Ω\Omega$ )	Reading 3 ( $Ω\Omega$ )	Mean ( $Ω\Omega$ )
5	219.95	220.05	220.00	220.00

Calculate the mean resistance of 1 resistor.

[2]

What was the resolution of the multimeter the technician used?

0.01 Ω
0.05 Ω
0.10 Ω
220.00 Ω

[1]

How do the results show that the technician's measurements were precise?

The measurements are accurate.
The measurements are grouped closely together.
The measurements are reproducible.

[1]

How would a graph of mean total resistance against the number of resistors show that the total resistance is directly proportional to the number of resistors?

The results give a line with a positive gradient starting from the y-axis.
The results give a straight line that would go through the origin.
The results show a linear relationship with a non-zero intercept.

[1]

Predict the mean total resistance of 12 of these resistors connected in series.

[2]

2.1 Current, potential difference and resistance

Question 30

Table 1

Markscheme

2.1 Current, potential difference and resistance

Question 30

Table 1

Markscheme

2.1 Current, potential difference and resistance

Question 30

Table 1

2.1 Current, potential difference and resistance Questions

2.1 Current, potential difference and resistance

Question 30

Table 1

2.1 Current, potential difference and resistance Questions