1.2 Limitation of physical measurements

• What are physical measurements used to quantify?

  Physical quantities
• What role do precise measurements play in technological development?

  Design, manufacturing, operation
• What is an example of a direct measurement?

  Length of an object using a ruler
• What is an example of an instrument limitation that causes systematic error?

  Inaccurate ruler scale
• Observer bias occurs when the person taking the measurements makes unconscious mistakes
• Accuracy is improved by reducing systematic errors, while precision is improved by reducing random errors.
• What process does physical measurements refer to?

  Quantifying physical quantities
• Order the types of physical measurements from fundamental to indirect:

  1️⃣ Fundamental Measurements

  2️⃣ Derived Measurements

  3️⃣ Direct Measurements

  4️⃣ Indirect Measurements
• What are derived measurements calculated from?

  Fundamental measurements
• Match the term with its definition:

  Accuracy ↔️ Closeness to the true value

  Precision ↔️ Closeness of repeated measurements
• What type of experiment reduces observer bias by keeping the observer unaware of the true value?

  Double-blind
• Using instruments with finer resolution reduces measurement variations.

  True
• Steps for managing random errors in measurements

  1️⃣ Take multiple measurements

  2️⃣ Calculate the average

  3️⃣ Use more precise instruments

  4️⃣ Stabilize environmental conditions
• Controlling environmental conditions involves stabilizing factors that can affect measurements
• Percentage error indicates the reliability of measurements.

  True
• Environmental factors such as temperature and humidity can affect measurement accuracy
• Steps highlighting the significance of physical measurements

  1️⃣ Describe the physical world

  2️⃣ Enable scientific progress

  3️⃣ Facilitate technological development
• What is observer bias in measurements?

  Unconscious mistakes by the observer
• What is the primary method for reducing random errors in measurements?

  Statistical averaging
• Random errors can be completely eliminated in measurements.

  False
• Accuracy and precision are interchangeable concepts in physical measurements.

  False
• What are the three techniques for managing random errors?

  Multiple measurements, precise instruments, environmental control
• Controlling environmental conditions involves stabilizing external factors and isolating the experiment from external disturbances
• What are the three key measurement limitations that affect data analysis?

  Instrument precision, environmental factors, observer error
• Accurate measurements are crucial for testing hypotheses in scientific research.


  True
• Derived measurements are calculated from two or more fundamental measurements.


  True
• Systematic errors are consistent and predictable, leading to a bias
• What does accuracy refer to in physical measurements?

  Closeness to the true value
• Match the concept with its description:

  Accuracy ↔️ Closeness to the true value

  Precision ↔️ Closeness of repeated measurements
• Why are precise measurements essential for technological development?

  Designing and operating technologies
• Instrument limitations can cause systematic errors in measurements.

  True
• What is the primary cause of instrument precision limitations in random errors?

  Sensitivity limitations
• Systematic errors can be reduced by ensuring instruments are properly calibrated
• What type of instruments should be employed to reduce measurement variations?

  Higher sensitivity instruments
• What type of disturbances should be isolated during an experiment to improve accuracy?

  Vibrations and electromagnetic interference
• Why are instruments with higher sensitivity used in measurements?

  Reduce measurement variations
• What is the formula for percentage error?

  \frac{\text{|Measured Value - True Value|}}{\text{True Value}} \times 100\%</latex>
• What is one example of a measurement limitation related to instrument precision?

  Sensitivity of measuring devices
• What is the effect of using a ruler with 1 mm resolution on the precision of measurements?

  Rounded to nearest millimeter
• Instrument limitations are a source of systematic errors.


  True