Class 10 (Science Assignment)

 

Scientific Study and Variables

Scientific study is a systematic process used to understand natural phenomena through observation, experimentation, and analysis. It relies on evidence rather than assumptions. One of the most important aspects of scientific investigation is identifying and controlling variables to ensure accurate and reliable results.

In any scientific experiment, three main types of variables are involved: independent variables, dependent variables, and controlled variables. The independent variable is the factor that the scientist deliberately changes to observe its effect. The dependent variable is the factor that is measured or observed as a result of changes in the independent variable. Meanwhile, controlled variables are factors that are kept constant throughout the experiment to ensure that the results are not affected by other influences.

For example, consider an experiment to study how sunlight affects plant growth. In this case, the amount of sunlight is the independent variable because it is being changed. The growth of the plant (such as its height) is the dependent variable because it depends on the amount of sunlight. Factors such as the type of plant, amount of water, and soil type must be kept constant; these are the controlled variables.

The scientific method involves several steps, including observation, hypothesis formation, experimentation, and conclusion. Identifying variables correctly is essential for designing a fair test. If variables are not properly controlled, the results may be unreliable or misleading.

Scientific study is important in everyday life and in national development. In Nepal, it helps improve agriculture, health, and environmental conservation. By understanding how variables affect outcomes, scientists can make better decisions and innovations that benefit society.

Tick the right answers of the following MCQs:

1.     What is the independent variable in an experiment?
A. The factor that is measured
B. The factor that is changed
C. The factor that is kept constant
D. The final result

2.     The dependent variable is:
A. The variable that is changed
B. The variable that is controlled
C. The variable that is measured
D. The variable that is ignored

3.     Controlled variables are:
A. Changed during the experiment
B. Measured at the end
C. Kept constant
D. Not important

4.     In the plant experiment, what is the dependent variable?
A. Sunlight
B. Soil type
C. Plant growth
D. Water

5.     Why are controlled variables important?
A. To confuse results
B. To ensure a fair test
C. To increase cost
D. To make experiments longer

6.     Which of the following is an example of an independent variable?
A. Plant height
B. Amount of sunlight
C. Soil type (if kept constant)
D. Plant type (if unchanged)

7.     What happens if variables are not controlled properly?
A. Results become more accurate
B. Results may be misleading
C. Experiment becomes shorter
D. Nothing changes

8.     Which step involves testing a hypothesis?
A. Observation
B. Experimentation
C. Conclusion
D. Communication

9.     Scientific study is based on:
A. Opinions
B. Traditions
C. Evidence
D. Guesswork

10.  What is the main purpose of identifying variables in an experiment?
A. To make it complicated
B. To design a fair and reliable test
C. To avoid experiments
D. To memorize definitions