Population Growth

Correct answer: A. When water sources are limited and growth is rapid

The correct answer is A: the effect will be greatest when water sources are limited and population growth is rapid. More people generally require more water for drinking, cooking, sanitation, homes, farming and economic activities. If the available water supply is already small, rapid growth can increase competition for water, lower per-person availability and intensify water stress. This does not mean that every growing population faces the same crisis; planning, conservation and efficient use can reduce pressure. Option B combines abundant water with slow growth, so demand is less likely to exceed supply. Option C is wrong because a declining population usually reduces growth-related demand. Option D is wrong because zero demand would cause no pressure on water resources. Memory cue: greatest water stress occurs when demand rises quickly but supply is limited.

Correct answer: B. Absolute growth may be limited

Answer: B. Growth rate is a percentage relative to the base population, while absolute growth is the actual number added. A high percentage on a small base can represent a modest number. For example, 20% growth on a base of 1 lakh adds 20,000 people, whereas 5% growth on a base of 100 lakh adds 5 lakh people. Thus, the smaller state may have the higher rate but the lower absolute increase. A is wrong because a percentage does not make the increase infinite. C is wrong because absolute growth can be calculated by subtracting the previous population from the current population. D is wrong because a high positive rate normally indicates an increase, although the actual number depends on the data. The word “may” is important: the absolute increase can be limited, not necessarily zero. Memory cue: rate tells proportion; absolute growth tells people added.

Correct answer: C. Absolute growth can still be very large

Correct answer: C, absolute growth can still be very large. Growth rate is a percentage, while absolute growth is the actual number added to the population. To calculate the approximate increase, multiply the base population by the growth rate expressed as a decimal. For example, 1% of 10 crore is 10 lakh, which is a large addition even though 1% is a low rate. Option A is wrong because a low rate does not make the increase zero; it would be zero only if there were no net increase. Option B is wrong because a positive growth rate still means an increase, not a decline. Option D is wrong because the rate remains useful for comparing population change. Memory cue: percentage tells the speed; the base tells the size of the actual increase.

Correct answer: D. Net migration

Correct answer: D, net migration. Population change has two broad components: natural change and migration. Natural increase is calculated from births minus deaths, whereas net migration is immigration minus emigration. If the birth rate is low, natural increase may be small, but a large number of people entering the area can still raise its total population. Option A is not the best answer because natural increase depends on births and deaths and is not the main factor described here. Option B is wrong because a death rate removes people and does not itself cause growth. Option C is wrong because sex ratio describes the balance between males and females, not the movement of people. Option D correctly identifies immigration-led growth. Memory cue: people entering minus people leaving equals net migration.

Correct answer: B. Twenty percent

Correct answer: B, twenty percent. Growth percentage is calculated using the increase divided by the previous population, multiplied by 100. The increase is 72 lakh − 60 lakh = 12 lakh. Therefore, growth percentage = (12 ÷ 60) × 100 = 20%. The unit lakh cancels because both numbers use the same unit. Option A is wrong because 12 is one-fifth of 60, not one-tenth. Option C confuses the numerical increase, 12 lakh, with the percentage; 12 lakh is not 12% of 60 lakh. Option D incorrectly uses the current or another unrelated base and does not follow the formula. A useful check is that 20% of 60 lakh equals 12 lakh, so the answer is consistent. Memory cue: percentage growth uses the old population as the denominator.

Correct answer: A. Twenty percent

Correct answer: A, twenty percent. Growth rate compares the increase with the previous population, which is the base. The increase is 16 lakh and the previous population is 80 lakh. Apply the formula: growth rate = (increase ÷ previous population) × 100 = (16 ÷ 80) × 100 = 20%. Because both figures are measured in lakh, the unit cancels and no conversion is needed. Option B is wrong because 16 lakh is the absolute increase, not the percentage. Option C reverses the relationship or treats the base as the smaller number; 16 is not 80% of 80. Option D is wrong because 8 lakh, not 16 lakh, would be 10% of 80 lakh. Always use the old population in the denominator. Memory cue: amount added over original amount, multiplied by 100.

Correct answer: B. Social factors are influencing fertility behaviour

Correct answer: B, social factors are influencing fertility behaviour. Education can improve awareness of health, family planning, and the economic effects of family size. A later average age of marriage can shorten the period in which people may have children. Together, these social patterns can be associated with a decline in birth rate, although the question does not claim they are the only causes. Option A is wrong because a falling birth rate does not prove that the death rate has increased. Option C is wrong because the information gives no evidence that migration has stopped. Option D is wrong because population density alone cannot explain the linked changes in education, marriage age, and fertility. The safest conclusion is that social conditions are affecting reproductive decisions. Memory cue: education and later marriage often influence the timing and number of births.

Correct answer: C. Pressure on housing and services will increase

Correct answer: C, pressure on housing and services will increase. More jobs can attract migrants and can also encourage existing residents to remain in or move toward the city. This raises demand for houses, water, sanitation, transport, schools, hospitals, and other urban services. If infrastructure expands more slowly than the population, shortages, overcrowding, higher rents, and longer waiting times may occur. Option A is wrong because unequal growth between population and services creates pressure rather than removing it. Option B is wrong because job opportunities generally attract people; the question gives no reason for automatic decline. Option D is impossible and does not describe a demographic or urban effect. The conclusion concerns capacity and demand, not the physical disappearance of the city. Memory cue: population grows faster than facilities, so demand exceeds supply.

Correct answer: D. Difference between births and deaths

Correct answer: D, the difference between births and deaths. Natural increase is defined as births minus deaths. Total population change can be written as natural increase plus net migration. Since net migration is zero, there is no addition or subtraction from people moving in or out, so total growth is determined by the natural increase alone. Therefore, it depends on the difference between births and deaths. Option A is wrong because area affects possible density, not the number added directly. Option B is wrong because density is a measure of people per unit area, not a component of population change. Option C is incomplete because deaths alone do not determine growth; births must also be considered. Option D correctly states the required difference. Memory cue: with migration balanced, births minus deaths controls the change.

Correct answer: A. Three lakh

Direct answer: A, three lakh. Population growth has two parts: natural increase and net migration. First calculate natural increase by subtracting deaths from births: five lakh births minus three lakh deaths equals two lakh. Then include net migration, because one lakh more people entered than left. Therefore, total growth = natural increase + net migration = two lakh + one lakh = three lakh. A is correct because it includes both components. B is only the natural increase and ignores migration. C is only the net migration and ignores births and deaths. D is obtained by adding all three figures without treating deaths as a reduction; deaths must be subtracted, not added. Memory cue: births minus deaths, then add net migration.

Correct answer: B. Small base population and limited actual increase

Direct answer: B. Percentage growth compares the increase with the starting, or base, population: percentage growth = increase ÷ base population × 100. A small number can be a large percentage when the base is very small. For example, an increase of 10 people over a base of 100 people is 10%, even though the absolute increase is only 10 people. A large base would usually require a much larger numerical increase to produce the same percentage. A is not the best answer because both the base and increase are large. C has no growth, so its percentage is zero. D cannot be used normally because percentage growth with a zero base is undefined. Memory cue: percentage depends on the base; absolute growth is the actual number added.

Correct answer: C. Population growth may become rapid

Direct answer: C, population growth may become rapid. Birth rate measures births, while child mortality measures how many young children die. If many children survive because child mortality falls, and births continue at a high level, the number of people added to the population can rise. The natural increase is broadly related to births minus deaths; fewer deaths make this difference larger when births remain high. A is not necessarily correct because the reduced mortality can speed growth. B is not supported: a fall in child mortality does not by itself cause population decline. D is unrelated, because mortality and birth conditions do not automatically stop migration. The word “may” is important: other factors, such as migration and later changes in fertility, can also affect the final result. Memory cue: high births plus fewer deaths usually means faster natural increase.

Correct answer: D. Slow or nearly stable

Direct answer: D, slow or nearly stable. Population change depends on births, deaths and migration. A low birth rate means relatively few people are added through births, while a low death rate means fewer people are removed. If migration is balanced, the number entering is approximately equal to the number leaving, so migration contributes little or no net change. With few births and balanced migration, the overall increase is likely to be small, although the exact result depends on the numerical difference between births and deaths. A is not supported because low births do not normally produce very rapid growth. B is too absolute: low birth and death rates do not necessarily make growth negative. C is impossible because population is not automatically unlimited. Memory cue: balanced migration cancels out; then compare births with deaths.

Correct answer: B. Total population has definitely decreased

Direct answer: B. A lower growth rate means that population is increasing more slowly, or that its change relative to the base population has become smaller. It does not automatically mean that the total population has fallen. For example, a population may grow by 2% in one period and 1% in the next; it is still growing in both periods, but more slowly in the second. A is a reasonable conclusion because the pace has reduced. C recognises that the rate, or proportion of change, has changed. D is important because rates must be compared with an earlier period and a clear base. B is wrong because a declining rate and a declining population are different ideas. Memory cue: falling growth rate is not the same as falling population.

Correct answer: A. Births and deaths are equal but immigration is high

Direct answer: A. Migration-based growth occurs when the main addition to a population comes from people moving into the area rather than from natural increase. Natural increase is births minus deaths. In A, births and deaths are equal, so natural increase is zero. However, immigration is high, meaning many people enter the area; therefore, the population can grow mainly because of migration. B describes natural growth through many births and gives no migration contribution. C describes high deaths with no immigration, which is unlikely to create growth and may reduce population. D changes the size of the area, not the number of people living in it. The relevant terms are immigration, people entering, and net migration. Memory cue: if births minus deaths is small but inward movement is large, growth is migration-led.

Correct answer: A. Because the difference between the birth rate and death rate may be small

Direct answer: A. Natural population growth is determined mainly by the difference between the birth rate and the death rate. If both rates are high and close to each other, many births are offset by many deaths, so the net increase can remain small. For example, a birth rate of 35 per thousand and a death rate of 32 per thousand gives a natural increase of only 3 per thousand. B is wrong because a high birth rate does affect growth; its effect is reduced when deaths are also high. C is wrong because deaths generally remove people and therefore reduce growth, not increase it. D is factually wrong: births do not make the death rate zero. Migration may also affect total growth, but it is not given here. Memory cue: compare the two rates, not either rate alone.

Correct answer: B. Check the combined effect of falling birth rate and falling death rate

Direct answer: B, examine the combined effect of both falling rates. Population growth depends on the relationship between births and deaths. Successful family planning generally lowers the birth rate, so fewer people are added naturally. A falling death rate works in the opposite direction: fewer people die, so more people remain in the population. To judge the final growth, compare the size and timing of both changes; do not assume that one factor alone determines the result. A is incomplete because birth rate is only one part of natural change. C is wrong because a lower death rate can substantially increase or maintain growth. D confuses migration with births; migration changes population through people entering or leaving, not through the birth rate. Memory cue: natural increase equals births minus deaths, while total change also considers migration.

Correct answer: C. Twenty percent

Direct answer: C, twenty percent. Begin by finding the increase: current population minus previous population equals 90 lakh − 75 lakh = 15 lakh. Percentage growth is calculated against the previous population, because that is the starting base. Therefore growth rate = (15 ÷ 75) × 100 = 20%. Another check is that 15 is one-fifth of 75, and one-fifth equals 20%. A is not obtained from the data. B treats the increase of 15 lakh as if it were automatically 15 percent, which is a common mistake; lakh is a number unit, not a percentage. D is also inconsistent with the calculation. The important rule is: percentage growth = increase ÷ original population × 100.

Correct answer: A. Because birth rate, education, migration and the economy also influence it

Direct answer: A. Health improvement is important because it can reduce deaths, improve survival and affect life expectancy, but population growth is a multi-factor process. Birth rate determines how many people are added through births. Education may influence knowledge, family-size decisions and the timing of marriage or childbearing. Migration changes the population of both the place people leave and the place they enter. Economic conditions affect employment, living standards, family decisions and movement. Therefore a complete explanation must consider several connected factors rather than health alone. B is false because health is strongly related to death rates. C is false because migration can be positive, negative or zero depending on movement. D is false because birth rate is measured using demographic data. A wins because it gives the required broader explanation.

Correct answer: A. Because the young base can affect future births

Direct answer: A. A population can show momentum when a large number of young people are approaching or entering the childbearing ages. Even if each person has fewer children and the birth rate is falling, the total number of births may remain substantial because the group capable of having children is large. This can keep population growth going for some time before the age structure changes. B is wrong because birth rate remains a meaningful measure of births relative to population. C is unsupported and unrealistic; a large young population does not make death rate zero. D is irrelevant because migration measurement is not the reason given here. The key idea is population momentum: age structure can delay the effect of falling fertility on total growth.

Correct answer: B. Negative

The direct answer is B: total growth will be negative. Population change depends mainly on natural change and net migration. Natural change equals births minus deaths. Here, the birth rate is lower than the death rate, so natural change is negative: more people die than are born. Net migration is also negative, meaning more people leave the area than enter it. Both effects reduce the population, so total growth is negative. Option A is wrong because neither component adds people. Option C is wrong because the two negative effects do not cancel; they work in the same direction. Option D is wrong because the information is sufficient to identify the direction of growth, even without exact numbers. Memory cue: births minus deaths plus net migration; two negative terms usually mean decline.

Correct answer: C. Forty percent

The direct answer is C: forty percent. First find the absolute increase: current population minus previous population = 28 lakh − 20 lakh = 8 lakh. Growth percentage is calculated using the previous population as the base: (increase ÷ previous population) × 100. Therefore, (8 ÷ 20) × 100 = 0.4 × 100 = 40%. Option A, 20%, does not follow the calculation. Option B, 30%, is another incorrect percentage. Option D, 8%, confuses the absolute increase of 8 lakh with a percentage. The old value must be used as the denominator because growth is measured relative to the starting population. Memory cue: percentage growth = increase ÷ old value × 100.

Correct answer: B. Pressure on social services

The direct answer is B: pressure on social services. Rapid population growth increases the number of people who need schools, teachers, hospitals, doctors, vaccination, sanitation, and other public facilities. If education and health services expand slowly, existing facilities must serve more people, causing overcrowding, longer waiting times, and unequal access. Option A is incomplete and not the standard effect: land area does not automatically create the main pressure described here. Option C is unrelated because population growth does not lead to a ban on census work. Option D is also unrelated; weather pressure is not the direct social consequence in the question. The important link is rapid growth plus slow service expansion. Memory cue: more people, same services = service pressure.

Correct answer: A. Growth may increase

The direct answer is A: growth may increase. Better food security can improve people’s nutritional condition and reduce deaths related to inadequate food. A lower death rate means the difference between births and deaths can become larger, so natural increase may rise, provided other factors do not offset it. The word “may” is important: the question does not give the birth rate or migration, so we should not claim that growth must increase in every case. Option B is wrong because a falling death rate does not by itself make growth negative. Option C is wrong because improved food security does not make the birth rate zero. Option D is unrelated; population can still be counted. Memory cue: fewer deaths can increase natural growth, but always check births and migration too.

Correct answer: B. Elderly health and care services

The direct answer is B: elderly health and care services. A low growth rate describes how quickly the total population is changing, but it does not tell us the age structure. If the proportion of elderly people is high, planning must consider their healthcare, regular medical support, accessible transport, social assistance, and long-term care needs. Option A may be useful for some residents but does not address the main planning need indicated by a large elderly population. Option C concerns water or infrastructure and is not specifically linked to age structure. Option D is harmful, irrelevant, and not a planning need. The lesson is to examine both population growth and age composition. Memory cue: growth rate tells “how fast”; age structure tells “who needs services.”