Measurement and Uncertainty

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What is the SI unit for mass?

The SI unit for mass is the kilogram (kg).

Define accuracy in measurements.

Accuracy refers to how close a measured value is to the true value.

What does precision in measurements refer to?

Precision refers to how close repeated measurements are to each other.

How is absolute uncertainty expressed?

Absolute uncertainty is the margin of error of a measurement, expressed in the same units as the measurement.

What is a systematic error?

A systematic error is a consistent, repeatable error associated with faulty equipment or flawed experiment design.

Name a common example of a random error.

A common example of a random error is fluctuation in electrical readings due to changes in temperature.

How do you calculate percentage uncertainty?

Percentage uncertainty is calculated by dividing the absolute uncertainty by the measured value and multiplying by 100.

What is meant by the term ‘resolution’ of a measuring instrument?

Resolution is the smallest change in a quantity being measured that can be detected by an instrument.

When combining uncertainties, which type should you add directly?

Absolute uncertainties should be added directly when combining multiple measurements.

What are base quantities in physics?

Base quantities are the fundamental quantities of measurement, such as length, mass, time, electric current, temperature, amount of substance, and luminous intensity.

Give an example of a derived quantity.

Velocity, which is derived from the base quantities of length and time, is an example of a derived quantity.

Why is calibration important for measurement devices?

Calibration ensures that a measurement device provides accurate readings by comparing it with a standard.

How can parallax errors be minimized?

Parallax errors can be minimized by ensuring measurements are taken at eye level and perpendicular to the measuring scale.

What is the purpose of significant figures in a measurement?

Significant figures communicate the precision of a measurement by showing which digits are meaningful and reliable.

How do you determine the number of significant figures to use in a result?

The number of significant figures in a result should match the measurement with the smallest number of significant figures involved in the calculation.