In 1981 , the r - value for human population in India was :

Options

A. 0.0196
B. 0.0205
C. 2.71
D. 0.175

Answer

To find the r-value for the human population in India in 1981, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the r-value**: The r-value, or intrinsic rate of natural increase, represents the growth rate of a population. It is calculated as the difference between the birth rate (b) and the death rate (d) per capita.

2. **Population Growth Equation**: The population growth can be expressed with the equation:
\[ \frac{dn}{dt} = (b - d) \cdot n \]
Here, \( \frac{dn}{dt} \) is the change in population over time, \( b \) is the birth rate, \( d \) is the death rate, and \( n \) is the current population size.

3. **Rearranging the Equation**: If we let \( r = b - d \), the equation simplifies to:
\[ \frac{dn}{dt} = r \cdot n \]
This shows that the population growth rate is directly proportional to the current population size.

4. **Historical Data**: To find the specific r-value for India in 1981, we refer to historical demographic data. According to the information provided, the r-value for India in 1981 was reported to be 0.0205.

5. **Conclusion**: Therefore, the r-value for the human population in India in 1981 is 0.0205.

### Final Answer:
The r-value for the human population in India in 1981 was **0.0205**.

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