Identifying Measurement Errors in Science

What is the term used to describe the difference between a measured value and the true value?

• Precision

• Error

• Accuracy

• Calibration

Answer explanation

The term 'Error' refers to the difference between a measured value and the true value. It quantifies how far off a measurement is from the actual value, distinguishing it from precision and accuracy.

Which type of error occurs due to unpredictable fluctuations in the measurement process?

• Systematic Error

• Random Error

• Gross Error

• Human Error

Answer explanation

Random error occurs due to unpredictable fluctuations in the measurement process, leading to variations that cannot be controlled. Unlike systematic errors, which are consistent, random errors are erratic and affect precision.

What is the main cause of systematic errors in scientific measurements?

• Faulty equipment

• Human mistakes

• Environmental changes

• Random fluctuations

Answer explanation

Faulty equipment is a primary source of systematic errors, as it consistently produces inaccurate measurements. Unlike random fluctuations or human mistakes, which can vary, faulty equipment leads to predictable and repeatable errors.

If a scale consistently reads 0.5 kg heavier than the actual weight, what type of error is this?

• Random Error

• Systematic Error

• Gross Error

• Human Error

Answer explanation

The scale's consistent overestimation of weight by 0.5 kg indicates a systematic error, as it consistently deviates from the true value in a predictable manner, rather than being random or due to human mistakes.

Which of the following is a method to reduce random errors?

• Calibrating instruments

• Taking multiple measurements and averaging

• Using faulty equipment

• Ignoring outliers

Answer explanation

Taking multiple measurements and averaging helps to minimize random errors by reducing the impact of fluctuations in individual measurements, leading to a more accurate and reliable result.

What is the term for errors that occur due to mistakes in reading instruments or recording data?

• Systematic Error

• Random Error

• Gross Error

• Calibration Error

Answer explanation

Gross errors are significant mistakes in data collection, often due to misreading instruments or recording data incorrectly. They differ from systematic and random errors, which are more predictable and less severe.

Which of the following is NOT a way to minimise systematic errors?

• Regular calibration of instruments

• Using high-quality equipment

• Taking repeated measurements

• Correcting for known biases

Answer explanation

Taking repeated measurements helps reduce random errors, not systematic errors. Systematic errors can be minimized through calibration, using quality equipment, and correcting known biases.

What is the effect of random errors on the precision of measurements?

• They increase precision

• They decrease precision

• They have no effect

• They improve accuracy

Answer explanation

Random errors introduce variability in measurements, leading to inconsistent results. This variability decreases precision, as precision refers to the repeatability of measurements. Therefore, the correct choice is that they decrease precision.

Which of the following is an example of a systematic error?

• A stopwatch that runs slow

• A sudden gust of wind affecting a balance

• A misread thermometer

• A power surge during an experiment

Answer explanation

A stopwatch that runs slow is a systematic error because it consistently gives inaccurate time measurements. In contrast, the other options represent random errors that can vary in their impact.

How can the accuracy of a measurement be improved?

• By increasing the number of measurements

• By using more precise instruments

• By calibrating instruments properly

• By using a larger sample size

Answer explanation

Calibrating instruments properly ensures they provide accurate readings by correcting any systematic errors. While increasing measurements and using precise instruments can help, proper calibration is essential for accuracy.