Population Growth

Correct answer: C. 10 percent

To find percentage population growth, first calculate the numerical increase and then compare it with the initial population. The population rises from 6 million to 6.6 million, so the increase is \(6.6-6=0.6\) million, or 600,000 people. Percentage growth is calculated using the initial population as the base: \((0.6/6)\times100=10\) percent.

Therefore, option C, 10 percent, is correct. The denominator must be the starting population, not the final population. The increase of 0.6 million is one-tenth of 6 million, which provides a quick check of the result. Six percent would understate the increase, while 8 or 11 percent do not follow from the stated change. This is total growth over the period, not necessarily an annual rate.

Correct answer: B. 800

Natural increase measures the change caused only by births and deaths. It is found by subtracting the number of deaths from the number of births: \(\text{natural increase}=\text{births}-\text{deaths}\). For this region, the calculation is \(2400-1600=800\). Therefore the population gains 800 people through natural increase.

The figures are counts of events during the same period, so no rate conversion is needed. Adding births and deaths gives 4000, but that is the total number of demographic events, not the net increase. The values 600 and 1000 do not result from the required subtraction. Hence option B, 800, is the correct choice.

Correct answer: A. Increase of 300

Total population change has two parts: natural change and net migration. Natural change is births minus deaths. Net migration is in-migrants minus out-migrants. The final answer must combine both results, because a country can have natural growth while losing people through migration. Positive values indicate an increase and negative values indicate a decrease.

Natural increase is \(2000-1500=500\). Net migration is \(700-900=-200\), because 200 more people leave than enter. The total is \(500+(-200)=300\), so the population increases by 300. Therefore option A is correct. Choosing 500 would count only births and deaths and would ignore the larger number of out-migrants.

Correct answer: B. 15 per thousand

Natural increase measures population change caused by births and deaths only. It does not include immigration or emigration. The standard calculation is the birth rate minus the death rate, using the same unit, such as per thousand population.

Here, the birth rate is 26 per thousand and the death rate is 11 per thousand. Therefore, \(26-11=15\) per thousand. This positive value means that, before considering migration, there are 15 more people per thousand than the number lost through deaths. Adding the two rates would be wrong because deaths reduce population. Thus, option B is correct.

Correct answer: B. 1.2 percent

The expression “per thousand” means a value out of 1,000. To convert it into a percentage, divide by 1,000 and multiply by 100, because a percentage is a value out of 100. Therefore, 12 per thousand is not 12 percent; it is a much smaller proportion.

The calculation is \(\frac{12}{1000}\times100=1.2\) percent. Hence option B is correct. Equivalently, 12 people in every 1,000 are one person in about 83.3, which is close to 1.2 in every 100. The values 0.12 percent and 12 percent result from incorrect conversion, while 120 percent is impossible for this rate.

Correct answer: C. 2 percent

The simple annual growth rate compares the number added during the year with the population at the beginning of that year. The formula is \(\frac{\text{increase}}{\text{initial population}}\times100\). Substituting the values gives \(\frac{30000}{1500000}\times100=2\%\). The unit descriptions, 30,000 and 1.5 million, are compatible because both are numbers of people.

Thus option C is correct. The answer is not 1 percent or 1.5 percent because those do not result from the required ratio. It is not 3 percent because the increase is only two out of every hundred people in the starting population. This is a simple rate and does not require compounding.

Correct answer: C. Increase of 70000

Total population change combines two components: natural increase and net migration. Natural increase is already given as 50,000, and net in-migration is positive 20,000, meaning more people entered the country than left it. Since both figures add to population, the total change is \(50{,}000 + 20{,}000 = 70{,}000\). The country therefore experiences an increase, not a decrease.

Option C is correct. Option A would incorrectly subtract the migration figure, option B would ignore migration, and option D would give the wrong direction as well as the wrong amount. A negative net migration would need to be subtracted, but the question specifically gives net in-migration of 20,000. Thus the total population rises by 70,000 people during the stated period.

Correct answer: A. Decrease of 15000

Total population change combines natural increase with net migration. Natural increase is already a signed value: positive 30000 means births exceed deaths by that amount. Net migration of -45000 means 45000 more people leave than enter. Adding these signed quantities gives the overall change, so the migration loss can outweigh the natural increase.

The calculation is \(30000 + (-45000) = -15000\), or \(30000 - 45000 = -15000\). Thus the province loses 15000 people overall, making option A correct. It is not a decrease of 45000 because natural increase offsets part of the migration loss. Nor is it an increase, since the negative migration balance is larger than the natural increase.

Correct answer: B. Naturally stable

Natural increase is the difference between the birth rate and the death rate. When both rates are 20 per thousand, the difference is zero. If there is also no migration, no additional people enter or leave the country through migration. Therefore, the total population is naturally stable in the sense of no net numerical change, so choice B is correct.

Calculate natural increase as \(20-20=0\) per thousand. Net migration is also zero, so total change is approximately zero. This does not mean that no births or deaths occur; it means their numbers balance each other. The population could still change in age structure or location, but the total number remains roughly constant. Rapid growth, rapid decline, and doubling are not supported by equal birth and death rates.

Correct answer: A. Birth rate remains above death rate but the gap keeps narrowing

A positive growth rate means births still exceed deaths, so the population continues to increase naturally. However, the size of that increase depends on the gap between the birth rate and the death rate. If the birth rate remains above the death rate but the gap becomes smaller, the growth rate stays positive while declining continuously. Therefore, option A is correct.

For example, a birth rate of 30 and death rate of 10 gives a gap of 20. Later, rates of 22 and 10 give a gap of 12. Growth remains positive, but it is slower. A positive rate does not mean the population is growing faster, and it does not by itself mean the total population is declining. The other options either produce zero, negative, or unrelated outcomes.

Correct answer: B. Population may begin growing again

Total population changes through natural increase or decrease and net migration. If the overall growth rate is zero at first, additions and losses are balanced at that time. Later, positive net migration means more people enter the country than leave it. Unless an exactly offsetting change in births and deaths occurs, these additional residents raise the total population. Thus a zero growth rate at one moment does not permanently fix the population.

Option B is correct because positive net migration can restart population growth. Option A would require total losses to exceed additions, which is not stated. Option C is too strong: migration does not make the population double immediately; the amount depends on the number of migrants and the initial population. Option D is false because migration directly changes the population count. The result depends on net migration, not merely the number entering without considering those leaving.

Correct answer: B. 300000

Natural increase is the number of births minus the number of deaths during the same period. It measures change caused by natural demographic processes and does not include migration. Here there are 900,000 births and 600,000 deaths. Subtracting deaths from births gives \(900,000 - 600,000 = 300,000\).

Therefore, option B is correct. The answer is positive because births exceed deaths by 300,000. The value 1,500,000 is the sum of births and deaths, which counts demographic events but does not measure the population increase. The figures 200,000 and 600,000 do not represent the required difference. If migration were given, it would be used separately to calculate total population change.

Correct answer: C. 0.6 million

A growth rate of 1.5 percent means 1.5 out of every 100 people are added during one year, under the simple calculation requested. The starting population is 40 million, or 40,000,000. Apply the rate as a fraction: \(40000000\times1.5/100\). This gives \(600000\), which is 0.6 million or 6 lakh.

Therefore, option C is correct. The calculation estimates the increase, not the new total population. The approximate population after one year would be 40.6 million if the rate remained applicable. In real demographic accounting, the exact figure may be affected by timing, changing rates, and compounding, but those complications are excluded by the question’s simple one-year instruction.

Correct answer: C. 1.2 million

Absolute increase is the simple numerical difference between the final population and the initial population. The country begins with 8 million people and ends with 9.2 million people. Therefore, the calculation is \(9.2-8.0=1.2\) million. In Indian numbering, 1.2 million equals 12 lakh, or 1,200,000 people.

Thus option C is correct. The ten-year period does not change the absolute increase; it only tells us how long the change took. The answer is not 0.8 million, because that number is one-tenth of the initial population, and it is not 2 million because that would overstate the difference. The supplied answer and calculation are correct.

Correct answer: C. 15 percent

Percentage growth is measured relative to the initial population. The population increases from 8 million to 9.2 million, so the absolute increase is 1.2 million. Dividing 1.2 million by the initial 8 million and multiplying by 100 gives 15 percent. Thus, choice C is correct.

The calculation is \(\frac{9.2-8}{8}\times100=\frac{1.2}{8}\times100=15\%\). In lakh units, the increase is 12 lakh out of an initial 80 lakh, so \(\frac{12}{80}\times100=15\%\). The value 12 is the absolute increase in lakh, not the percentage. Choice A is too low, choice B confuses the increase with a rate, and choice D overstates the change.

Correct answer: B. Population may still be growing but more slowly

A growth rate of 1.5 percent is still positive. It means the population is increasing, although it is increasing more slowly than it did at 2.5 percent. A fall in the rate is not the same as a fall in the population. Population decline would require a negative growth rate, unless a more specific context changed the interpretation.

The change from 2.5 percent to 1.5 percent shows a slowdown in the pace of growth. It does not prove that deaths exceed births, that population has become stable, or that the population must be declining. Therefore option B is correct: the population may still be growing, but more slowly. The word “may” is suitable because other components, such as migration, can also affect total population.

Correct answer: A. Doubling time will generally be shorter

Doubling time is the period required for a population to become twice its present size. If the growth rate is high and remains steady, population is added more rapidly each year. Consequently, it reaches twice its starting size in less time than it would at a lower rate.

The Rule of 70 gives the approximate relationship: doubling time \(\approx70\div\) annual growth rate. Since the rate is in the denominator, a higher rate generally produces a shorter doubling time. Therefore option A is correct. This conclusion assumes that the rate remains consistently high and that other conditions do not substantially change. The other choices either reverse this relationship or deny the possibility of doubling.

Correct answer: B. 28 years

The Rule of 70 is a quick estimate for the time needed for a quantity to double when its annual growth rate is approximately constant. The estimated doubling time in years is found by dividing 70 by the annual rate expressed as a percentage. It is an approximation, not a guarantee, because actual rates may change over time.

For an annual growth rate of 2.5 percent, doubling time is \(70\div2.5=28\) years. Therefore, option B is correct. The rule shows why higher growth rates produce shorter doubling times: the same number, 70, is divided by a larger rate. The estimate assumes positive growth and does not describe a population with a falling or highly variable rate.

Correct answer: D. 140 years

The Rule of 70 estimates doubling time by dividing 70 by the annual growth rate in percent. A low rate produces a long doubling period because population adds only a small fraction each year. The result is approximate and assumes that the rate remains broadly constant over the period.

Using the given rate, doubling time is \(70\div0.5=140\) years. Therefore, option D is correct. A doubling time of 70 years would correspond to a 1 percent annual rate, since \(70\div1=70\). This comparison helps identify why 70 years is not correct here: the stated rate is only half of 1 percent, so the estimated time is twice as long.

Correct answer: B. A large number of people are in reproductive ages

Correct answer: B, a large number of people are in the reproductive-age group. Fertility rate means the average number of children born per woman, whereas the total number of births also depends on how many women are in childbearing ages. Earlier high fertility may have produced a very large young population. When this large group reaches reproductive age, many births can occur even after the average number of children per woman begins to fall. This continuing effect is called demographic momentum. A is wrong because fertility directly affects births, although it is not the only factor. C is wrong because the death rate does not explain why births remain high. D is wrong because stopping migration does not by itself create a large number of births. Memory cue: falling fertility does not immediately mean falling births when the reproductive-age population is large.

Correct answer: B. Very large young population

Age structure shows how many people belong to different age groups. A very large young population means that many people will reach working and reproductive ages in the future. Even if each family has fewer children, the large number of potential parents can keep the total number of births relatively high. This effect is often called population momentum.

Therefore, option B is correct. A large elderly population generally has less potential to produce future births because most members are beyond reproductive ages. A population containing only middle-aged people does not usually provide the same broad future base, and the absence of all age groups is impossible as a useful population structure. The answer concerns demographic potential, not a guarantee of unlimited growth.

Correct answer: B. Natural increase may become low or negative

Natural increase depends mainly on the balance between births and deaths. A low birth rate means fewer new people are added. If the share of elderly people is rising, deaths may become relatively more numerous because older populations generally contain more people at ages when mortality is higher. Consequently, the difference between births and deaths can become small or fall below zero.

Therefore, option B is correct: natural increase may become low or negative. This is a likely outcome, not an unavoidable one, because migration and age-specific mortality can affect total population and the exact rate. Low births do not automatically rise, and the population cannot be assumed to double. Options A, C, and D contradict the demographic relationship described.

Correct answer: B. The working-age share may increase

Migration is often selective by age because young adults are especially likely to move for employment. If a city receives many young workers, the number and share of people in the working-age group can rise immediately. Therefore option B gives the most reasonable age-structural effect. This does not mean every age group changes equally or that children disappear.

Age structure describes the proportion of people in different age groups. The incoming workers add directly to the working-age population and may make that group a larger share of the city total. The elderly share does not necessarily increase, and all age groups will not become equal. The wording says the share may increase, which appropriately allows for other population changes.

Correct answer: A. The age structure may become older

Migration is selective when particular age groups move more than others. If many young adults leave a district, the district loses a large share of people in working and reproductive ages. Even if people of other ages remain, the age composition changes. The proportion of older residents can consequently become larger among those left behind.

Therefore, option A is the most likely additional change: the age structure may become older. This does not mean every resident becomes older or that ageing is certain in every case; it means the average composition may shift toward older age groups. The other options are not logical consequences. Birth rates do not always double, land area does not shrink because of migration, and deaths cannot stop completely.

Correct answer: A. Births greatly exceed deaths

Natural increase means the excess of births over deaths. If population growth is mainly driven by high natural increase, the country must have many more births than deaths. Migration may also affect total population, but it is not the main factor in the situation described. Therefore, choice A is correct.

The basic relationship is \(\text{natural increase}=\text{births}-\text{deaths}\). A high positive result occurs when births greatly exceed deaths. Equal births and deaths would produce zero natural increase, while greater out-migration could reduce total population but would not itself create high natural increase. Thus choices B, C, and D either describe migration or a zero difference and do not match the stated cause.