Question

When will the population density increase, under special conditions?
When the number of :

• A. Deaths exceeds number of births and also number of emigrants equals number of immigrants.
• B. Births plus number of immigrants equals number of deaths plus number of emigrants.
• C. Births plus number of emigrants is more than the number of deaths plus number of immigrants.
• D. Births plus number of immigrants is more than the sum of number of deaths and number of emigrants.

Answer 1

The Correct Option is D

To determine when population density will increase under special conditions, let's consider the factors influencing population changes:

• Birth Rate: This adds to the population. A high birth rate increases population density.
• Death Rate: This reduces the population. A high death rate decreases population density.
• Immigration: This involves people moving into the place, increasing the population density.
• Emigration: This involves people moving out of the place, decreasing the population density.

Given the options, we are looking for conditions under which the sum of births and immigration outweighs the sum of deaths and emigration. Let's evaluate each option:

1. Deaths exceeds number of births and also number of emigrants equals number of immigrants
   If deaths exceed births, the population is decreasing due to higher mortality. Equal numbers of emigrants and immigrants have no net effect on population change. Thus, population density is likely to remain the same or decrease.
2. Births plus number of immigrants equals number of deaths plus number of emigrants
   In this scenario, the increase in population due to births and immigrants exactly offsets the decrease due to deaths and emigrants. This balance results in no net change in population density.
3. Births plus number of emigrants is more than the number of deaths plus number of immigrants
   Here, the factor of more births plus emigration actually means the net addition of population (from births) is being undermined by emigration, while adding immigrants. This does not necessarily mean a net increase in population density unless emigrants are fewer than deaths, which is not specified here.
4. Births plus number of immigrants is more than the sum of number of deaths and number of emigrants
   In this case, the sum of income (births and immigrants) is greater than outgoing (deaths and emigrants), clearly showing an increase in population. Hence, this is the correct condition for an increase in population density.

Conclusion: The correct answer is that the population density will increase when the "Births plus number of immigrants is more than the sum of number of deaths and number of emigrants."