Topic 11: Part 1 - Measurement/Data Processing Flashcards

1
Q

What is qualitative data?

A

Non-numerical information obtained from observations. Eg. colour changes, bubbling.

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2
Q

What is quantitative data?

A

Information obtained from measurements and associated with random errors/uncertainties.

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3
Q

What is the uncertainty of an analogue scale?

A

Half of the smallest division.

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4
Q

What is the uncertainty of a digital scale?

A

The smallest scale division. Eg. 1.068 would be 1.068±0.001

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5
Q

What are random errors?

A

Errors of precision. Can be minimised by repeated measurements.

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6
Q

What are random errors caused by?

A
  • Changes in the environment eg. temperature
  • The observer misinterpreting the reading
  • Insufficient data
  • The readability of the measuring instrument
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7
Q

What are systematic errors?

A

Errors of procedure (to do with accuracy). These can be reduced by careful experiment design.

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8
Q

What are systematic errors caused by?

A
  • Consistently measuring from the top instead of the bottom of the meniscus
  • Overshooting volume of a liquid
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9
Q

Define accuracy.

A

How similar the results are to the expected.

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10
Q

Define precision.

A

How similar the results are to each other.

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11
Q

How do we calculate uncertainties with addition and subtraction?

A

By adding the uncertainties. Use the half range rule.

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12
Q

How do we calculate uncertainties when multiplying or dividing? (+ significant figures rule)

A

The sum of the individual percentage uncertainties. The answer is quoted to the same number of significant figures as the least precise data.

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