Answer:

Introduction:
The collected data regarding the percentage of students who got grade A1 in Mathematics during the last 10 years in Board examinations is known as secondary data.

Definition of Secondary Data:
Secondary data refers to the data that is collected by someone else for a different purpose but can be used by others for their own research or analysis. It is data that has been previously collected and is readily available for use.

Explanation:
In this case, the curious 12th class student wants to collect the data regarding the percentage of students who got grade A1 in Mathematics during the last 10 years in Board examinations. Since the data is already collected and available, the student does not need to conduct any primary research to gather the required information. Instead, the student can rely on the existing data collected by the education board or other sources.

Advantages of Secondary Data:
1. Time-Saving: Secondary data saves time as it is readily available and eliminates the need for primary data collection.
2. Cost-Effective: Secondary data is cost-effective as it does not require resources to collect the data.
3. Large Sample Size: Secondary data often has a larger sample size, which increases the reliability and generalizability of the findings.
4. Historical Analysis: Secondary data allows for a long-term analysis of trends and patterns over time.

Limitations of Secondary Data:
1. Limited Control: The researcher has no control over the design and collection methods of the data.
2. Data Quality: The accuracy, relevance, and reliability of the data may vary, and the researcher needs to critically evaluate the quality of the data.
3. Lack of Specificity: Secondary data may not provide the specific information required for the research question, and the researcher may need to make compromises or assumptions.
4. Outdated or Incomplete Information: The data may be outdated or incomplete, and the researcher needs to consider this while interpreting the findings.

In conclusion, the collected data regarding the percentage of students who got grade A1 in Mathematics during the last 10 years in Board examinations is considered secondary data. This type of data has advantages such as time and cost savings, large sample size, and historical analysis, but it also has limitations such as limited control, data quality issues, lack of specificity, and outdated or incomplete information.