Variables and Hypotheses Practice Quiz (5 questions)

1. A student tests how water temperature affects the time sugar takes to dissolve, recording the time for each trial. Which variable is the dependent variable?

A. The water temperature

B. The time taken for the sugar to dissolve

C. The type of sugar used

D. The amount of water kept in each trial

Answer: (B)

Explanation

The dependent variable is what is measured, so it is the dissolving time recorded for each trial. Water temperature is the variable being changed; the amount of water and sugar type are conditions rather than the measured outcome.

2. A student changes the amount of light plants receive and records their growth. Which variable is the independent variable?

A. The plants’ recorded growth

B. The ruler used to measure growth

C. The number of plants measured

D. The amount of light provided

Answer: (D)

Explanation

The independent variable is the variable the experimenter changes or tests, which here is the amount of light. Plant growth is the measured outcome, and the other choices are not the tested input.

3. Which form correctly expresses a scientific hypothesis involving the variables in an experiment?

A. An if–then statement involving an independent and a dependent variable

B. A statement naming only the variable that is measured

C. A question asking what result an experiment will produce

D. A statement answering the question after results are collected

Answer: (A)

Explanation

A hypothesis is framed as an if–then statement and includes both the independent and dependent variables. Naming just the measured variable omits one variable, while an after-results answer describes a conclusion.

4. A lab diagram has straight, ruler-drawn lines and word labels, but the lines were drawn in ink. What change would bring it in line with the diagram conventions?

A. Keep the ink and replace word labels with symbols

B. Redraw it in pencil while keeping the ruler and word labels

C. Redraw it freehand while keeping the ink and word labels

D. Keep the ink and remove the ruler-drawn lines

Answer: (B)

Explanation

The conventions call for pencil, a ruler, and word labels, so the ink should be replaced with pencil while the other compliant features remain. Changing the label format or removing ruler use does not correct the medium.

5. A student is preparing a scientific diagram for a lab report. Which approach follows the diagram conventions?

A. Draw it in pencil with a ruler and label it using words

B. Draw it in pencil with a ruler and leave features unlabeled

C. Draw it in pencil freehand and label it using words

D. Draw it with a ruler in ink and label it using words

Answer: (A)

Explanation

A diagram should be drawn in pencil, made with a ruler, and labeled with words. Freehand drawing omits the ruler convention, ink replaces pencil, and unlabeled features omit word labels.