Define fiducial marker .

A fixed reference point used to improve timing accuracy, for example by sighting a pendulum as it passes the marker at its highest speed.

A weighted line used to check that a setup is aligned vertically.

Why is it better to time 10 oscillations of a pendulum and divide by 10, rather than timing one oscillation?

It reduces the effect of human reaction time error on the calculated time period, since the same absolute error is spread over a much longer total time.

How can two set squares be used to measure the diameter of a cylinder more accurately than a ruler alone?

The set squares are placed on either side of the cylinder so the ruler is held perpendicular to the cylinder's edges, giving an accurate reading instead of an estimate by eye.

What is the purpose of a set square when measuring the extension of a spring?

It checks that the ruler is vertical and parallel to the spring, so the extension reading is accurate.

A .......... acts as a fixed reference point, allowing a pendulum's oscillations to be timed as it passes through the point at its highest speed.

A fiducial marker acts as a fixed reference point, allowing a pendulum's oscillations to be timed as it passes through the point at its highest speed.

True or False? Timing a pendulum over a single oscillation gives a more accurate time period than timing 10 oscillations and dividing by 10.

False. Timing over many oscillations reduces the proportional effect of reaction time error, giving a more accurate value for the time period.

Define absolute uncertainty of a set of repeat readings.

Half the range of the repeat readings for that quantity.

How many repeat readings should typically be taken for a measurement in an experiment?

A good number of repeats is between three and five.

Why are repeat readings taken and averaged?

Averaging repeats increases precision, increases confidence in the result and checks that the measurements are reproducible rather than a one-off fluke.

Results should be recorded to a number of decimal places that is consistent with the .......... of the measuring instrument.

Results should be recorded to a number of decimal places that is consistent with the resolution of the measuring instrument.

True or False? Increasing the number of repeat readings always removes systematic error from a measurement.

False. Averaging repeat readings only reduces random error. A systematic error affects every reading equally and remains after averaging.

Define the range of readings in an experiment.

The spread of values of the independent variable used, chosen to be as wide as practically possible while respecting the limits of the apparatus.

What is considered a good range of values to record in an experiment?

Between five and ten values, with equal steps of 1, 2, 5 or a multiple of 10.

Why should the intervals between readings in a range be equal?

An equal step size gives a consistent spacing of data, making trends easier to identify and analyse, for example on a graph, rather than an uneven spacing such as 1, 2, 5, 6.

Give one reason to take as wide a range of readings as is practical.

A wider range shows whether the pattern in the results holds true across all values, or reveals a different pattern beyond a certain value that a narrow range would miss.

When choosing the range of a variable, the .......... of the apparatus must be considered, such as avoiding stretching a spring past its elastic limit.

When choosing the range of a variable, the limitations of the apparatus must be considered, such as avoiding stretching a spring past its elastic limit.

True or False? A wider range of readings is always better, regardless of the time available to complete the experiment.

False. While a wider range is generally better, the range chosen must also be practical to complete within the time available for the experiment.

Define significant figures .

The digits in a number that are reliable and necessary to indicate its quantity.

How many significant figures does 0.00079 have?

Two significant figures. Zeros before all non-zero digits are not significant.

How many significant figures does 57 000 have (no decimal point given)?

Two significant figures. Zeros after non-zero digits, in a number without a decimal point, are not significant.

Why must data within a single column of a results table be recorded to the same number of significant figures?

So the precision of the recorded data is consistent throughout that variable, which is required when the data is plotted on a graph or used in further calculations.

When rounding, the digit after the last required significant figure is used as the .......... to decide whether to round up or down.

When rounding, the digit after the last required significant figure is used as the rounder decider to decide whether to round up or down.

True or False? Zeros that come before all non-zero digits in a number, such as in 0.0079, are significant figures.

False. Leading zeros before non-zero digits are never significant, so 0.0079 has only two significant figures (7 and 9).

SI unit of electrical capacitance.

SI unit of stress and pressure.

True or False? The unit m 2 is the correct SI unit for volume.

False. The unit m 2 is used for area. Volume is measured in m 3 .

Define an anomalous result .

A result that is inconsistent with the trend of the other data, typically differing from the mean by more than 10%.

What should be done with an anomalous result when calculating a mean?

It should be ignored (excluded) from the mean calculation, and the measurement repeated if possible.

How can an anomalous result be identified on a graph?

It is a data point that does not fit the trend or line of best fit of the rest of the data.

A result is often considered anomalous if it does not fit the .......... shown by the rest of the data.

A result is often considered anomalous if it does not fit the trend shown by the rest of the data.

True or False? Anomalous results should be included in the mean but given less weight.

False. Anomalous results should be excluded entirely from the mean calculation, not included with reduced weight.

International A Level (IAL)PhysicsEdexcelFlashcards6. Practical Skills in Physics IIPractical Skills II: Implementation & Measurements

Practical Skills II: Implementation & Measurements (Edexcel International A Level (IAL) Physics): Flashcards

Exam code: YPH11

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FrontEvaluating Experiments
Define fiducial marker.

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Cards in this collection (38)

Define fiducial marker.
A fixed reference point used to improve timing accuracy, for example by sighting a pendulum as it passes the marker at its highest speed.
Define plumb line.
A weighted line used to check that a setup is aligned vertically.
Why is it better to time 10 oscillations of a pendulum and divide by 10, rather than timing one oscillation?
It reduces the effect of human reaction time error on the calculated time period, since the same absolute error is spread over a much longer total time.
How can two set squares be used to measure the diameter of a cylinder more accurately than a ruler alone?
The set squares are placed on either side of the cylinder so the ruler is held perpendicular to the cylinder's edges, giving an accurate reading instead of an estimate by eye.
What is the purpose of a set square when measuring the extension of a spring?
It checks that the ruler is vertical and parallel to the spring, so the extension reading is accurate.
A .......... acts as a fixed reference point, allowing a pendulum's oscillations to be timed as it passes through the point at its highest speed.
A fiducial marker acts as a fixed reference point, allowing a pendulum's oscillations to be timed as it passes through the point at its highest speed.
True or False?
Timing a pendulum over a single oscillation gives a more accurate time period than timing 10 oscillations and dividing by 10.
False.
Timing over many oscillations reduces the proportional effect of reaction time error, giving a more accurate value for the time period.
Define absolute uncertainty of a set of repeat readings.
Half the range of the repeat readings for that quantity.
How many repeat readings should typically be taken for a measurement in an experiment?
A good number of repeats is between three and five.
Why are repeat readings taken and averaged?
Averaging repeats increases precision, increases confidence in the result and checks that the measurements are reproducible rather than a one-off fluke.
To how many decimal places should readings from a micrometer of resolution 0.01 mm be recorded?
Two decimal places.
Results should be recorded to a number of decimal places that is consistent with the .......... of the measuring instrument.
Results should be recorded to a number of decimal places that is consistent with the resolution of the measuring instrument.
True or False?
Increasing the number of repeat readings always removes systematic error from a measurement.
False.
Averaging repeat readings only reduces random error. A systematic error affects every reading equally and remains after averaging.
Define the range of readings in an experiment.
The spread of values of the independent variable used, chosen to be as wide as practically possible while respecting the limits of the apparatus.
What is considered a good range of values to record in an experiment?
Between five and ten values, with equal steps of 1, 2, 5 or a multiple of 10.
Why should the intervals between readings in a range be equal?
An equal step size gives a consistent spacing of data, making trends easier to identify and analyse, for example on a graph, rather than an uneven spacing such as 1, 2, 5, 6.
Give one reason to take as wide a range of readings as is practical.
A wider range shows whether the pattern in the results holds true across all values, or reveals a different pattern beyond a certain value that a narrow range would miss.
When choosing the range of a variable, the .......... of the apparatus must be considered, such as avoiding stretching a spring past its elastic limit.
When choosing the range of a variable, the limitations of the apparatus must be considered, such as avoiding stretching a spring past its elastic limit.
True or False?
A wider range of readings is always better, regardless of the time available to complete the experiment.
False.
While a wider range is generally better, the range chosen must also be practical to complete within the time available for the experiment.
Define significant figures.
The digits in a number that are reliable and necessary to indicate its quantity.
How many significant figures does 0.00079 have?
Two significant figures. Zeros before all non-zero digits are not significant.
How many significant figures does 57 000 have (no decimal point given)?
Two significant figures. Zeros after non-zero digits, in a number without a decimal point, are not significant.
Why must data within a single column of a results table be recorded to the same number of significant figures?
So the precision of the recorded data is consistent throughout that variable, which is required when the data is plotted on a graph or used in further calculations.
When rounding, the digit after the last required significant figure is used as the .......... to decide whether to round up or down.
When rounding, the digit after the last required significant figure is used as the rounder decider to decide whether to round up or down.
True or False?
Zeros that come before all non-zero digits in a number, such as in 0.0079, are significant figures.
False.
Leading zeros before non-zero digits are never significant, so 0.0079 has only two significant figures (7 and 9).
farad (F)
SI unit of electrical capacitance.
pascal (Pa)
SI unit of stress and pressure.
What is the SI unit of electromotive force?
The volt (V).
What is the SI unit of magnetic flux density?
The tesla (T).
Derive the unit of resistivity, ρ, from the equation $ρ = \frac{R A}{L}$ , where R is resistance (Ω), A is area (m²) and L is length (m).
$[ρ] = \frac{Ω m^{2}}{m} = Ω m$
In the resistivity equation $ρ = \frac{R A}{L}$ , the area, A, is measured in units of ...........
In the resistivity equation $ρ = \frac{R A}{L}$ , the area, A, is measured in units of m².
True or False?
The unit m² is the correct SI unit for volume.
False.
The unit m² is used for area. Volume is measured in m³.
Define an anomalous result.
A result that is inconsistent with the trend of the other data, typically differing from the mean by more than 10%.
What should be done with an anomalous result when calculating a mean?
It should be ignored (excluded) from the mean calculation, and the measurement repeated if possible.
How can an anomalous result be identified on a graph?
It is a data point that does not fit the trend or line of best fit of the rest of the data.
A student records repeat currents of 2.5, 2.8, 6.1, 2.0 and 2.3 mA. Calculate the mean current.
6.1 mA is anomalous and is excluded:
$mean = \frac{2.5 + 2.8 + 2.0 + 2.3}{4} = 2.4 mA$
A result is often considered anomalous if it does not fit the .......... shown by the rest of the data.
A result is often considered anomalous if it does not fit the trend shown by the rest of the data.
True or False?
Anomalous results should be included in the mean but given less weight.
False.
Anomalous results should be excluded entirely from the mean calculation, not included with reduced weight.

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