Introduction:
Gross Domestic Product (GDP) is a measure of the total value of goods and services produced within a country's borders during a specific period. It is often used as an indicator of a country's economic health and growth. When the GDP of a country increases, it tends to have several positive effects on the economy, one of which is an increase in the disposable income of people.

Explanation:
1. Rise in GDP:
When the GDP of a country rises, it means that the total value of goods and services produced within the country has increased. This indicates that businesses are producing more, and the overall economic activity is growing.

2. Increase in Disposable Income:
One of the key effects of a rise in GDP is an increase in the disposable income of people. Disposable income refers to the income that individuals have available to spend or save after paying taxes and other essential expenses.

3. Increased Employment:
When the GDP of a country increases, it often leads to increased employment opportunities. Businesses expand their operations, create new jobs, and hire more workers to meet the growing demand for goods and services. This, in turn, leads to an increase in the overall income of individuals.

4. Wage Growth:
With the increase in employment, there is often an upward pressure on wages. As businesses compete for a limited pool of workers, they may offer higher wages to attract and retain talent. This results in wage growth, which contributes to an increase in the disposable income of people.

5. Business Expansion:
A rise in GDP indicates that businesses are doing well and generating higher profits. This gives them the confidence and financial resources to expand their operations. Business expansion leads to increased investment, job creation, and higher incomes for individuals.

Conclusion:
In conclusion, a rise in GDP leads to an increase in the disposable income of people. This is due to increased employment, wage growth, and business expansion, which contribute to higher overall incomes. The rise in disposable income allows individuals to have more money available for spending and saving, which in turn stimulates economic growth and further increases GDP.