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Class 9 · Science
→In an ideal fair experiment, which relationship among independent, dependent and controlled variables is correct?
Class 9 · Science
→A student tests the cleaning ability of three soaps, but the initial stain size differs on each cloth. Which would be the fairest dependent variable?
Class 9 · Science
→If the independent-variable values are correct but the dependent variable is measured by a different method each time, which quality is most affected?
Class 9 · Science
→A student calls room temperature the independent variable but does not change it or set it at different levels during the experiment. What is the best correction?
Class 9 · Science
→In which situation would a control group be most useful?
Class 9 · Science
→A student drops a ball from four different heights and measures its bounce height. If a different type of ball is used each time, what is the most appropriate improvement?
Class 9 · Science
→In an experiment, a student records the distance that a falling ruler travels before being caught in order to estimate reaction time. What is this distance?
Class 9 · Science
→Which option lists the independent, dependent, and controlled variables in the correct order when testing the effect of fertilizer amount on plant dry mass?
Class 9 · Science
→A student investigates whether music type affects reading speed. The sound intensity differs between music types. What should be done for a fair test?
Class 9 · Science
→In an investigation salt concentration is the independent variable. Which option is the best set of its levels?
Class 9 · Science
→If a controlled variable cannot be kept perfectly constant what is the best scientific step?
Class 9 · Science
→A student tests the effect of temperature on bacterial growth but allows different temperature groups to grow for different durations. What type of variable has incubation time become?
Class 9 · Science
→Three measurements are taken at each value of the independent variable. What is the main benefit?
Class 9 · Science
→One student records plant height by eye as short or tall. Another measures it in centimeters with a ruler. Why is the second student's dependent variable better?
Class 9 · Science
→While testing the effect of water amount on plant growth one plant is kept near a window and another in a dark corner. What is the light condition?
Class 9 · Science
→Two students use the same independent variable but one records time in seconds and the other in minutes. What is necessary before comparison?
Class 9 · Science
→While measuring the period of pendulums of different lengths the mass of the bob is kept constant. What is the purpose of keeping mass constant?
Class 9 · Science
→A student says that the variable placed on the horizontal axis is always the independent variable. What is the most accurate evaluation?
Class 9 · Science
→If the dependent variable first increases and then decreases as the independent variable rises what is the risk of taking only the first two values?
Class 9 · Science
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