Science
Variables in an experiment
In Class 9 Science, within “Exploration: Entering the World of Secondary Science,” students learn how variables shape a scientific experiment. They distinguish the independent variable that is deliberately changed, the dependent variable that is measured, and controlled variables kept constant for a fair test. The topic develops skills in planning investigations, recording observations, comparing results, identifying patterns, and drawing evidence-based conclusions while recognising sources of error.
Topic overviewटॉपिक का परिचय
Concept revisionअवधारणाओं का पुनरावर्तन
Which question tests the relationship between light and germination?
Option A changes the light condition and compares the rate of germination, so it tests the relationship between light and germination. Options B, C, and D test the effects of water, seed size, and temperature respectively, not light.
What should be the same while comparing two groups?
For a fair comparison, both groups must be measured using the same method. For example, temperature in both groups should be measured with the same type of thermometer and procedure.
Why are factors other than water kept the same while studying plant growth?
Plant growth is affected by several factors, such as light, soil, temperature, and type of seed. If these are kept the same, any difference in growth can be linked to the amount of water only.