OSAT OSAT Scientific Inquiry and Principles 4

Question 1

A student measures the length of a pencil as 14.2 cm, 14.1 cm, and 14.3 cm in three trials. The actual length is 14.2 cm. These measurements are best described as:

Accepted Answer

Both accurate and precise

Answer

The measurements cluster closely together (precise) and are centered on the true value (accurate), so they are both.

Question 2

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

Accepted Answer

A balance that consistently reads 2 grams too heavy

Answer

Systematic errors consistently skew results in the same direction, such as a miscalibrated instrument.

Question 3

When designing an experiment, operational definitions are used to:

Accepted Answer

Explain how variables will be measured

Answer

Operational definitions specify exactly how a variable will be measured or manipulated in a study.

Question 4

A student's experiment shows that caffeine increases heart rate. To strengthen this conclusion, the student should:

Accepted Answer

Increase the number of trials and subjects

Answer

Increasing the number of trials and subjects reduces variability and strengthens the reliability of conclusions.

Question 5

Which SI unit is used to measure the amount of a substance?

Accepted Answer

Mole

Answer

The mole (mol) is the SI base unit for the amount of substance, defined by Avogadro's number.

OSAT Test Practice Test

OSAT Test Practice Test

OSAT OSAT Scientific Inquiry and Principles 4