The sex ratio is the ratio of males to females in a population. In most sexually reproducing species, the ratio tends to be 1:1. 

In May 1854, the Bombay–Thane line was extended to Kalyan with the Thane viaducts over the Thane creek (India's first railway bridges).

The first railway line in India was constructed during the rule of Lord Dalhousie. The first train started from Bori Bunder in Bombay at 3:35 pm on April 16, 1853 with a 21-gun salute. It had 14 carriages.

The agricultural sector accounted for the largest share of the workforce which was around 70-75%. The manufacturing and the services sectors accounted for only 10 and 15-20 percent respectively. Also, there were increasing regional variations under the British rule.

The state of infrastructure during the pre-British India was very poor. The transportation and communication lines were below average due to insufficient funds. In fact, most of the villages lacked connectivity by pucca roads. Consequently, natural dusty tracks were the roads predominant in India. However, such roads spelt misery during monsoons as they became muddy and difficult to traverse.  During natural calamities, these roads became unfunctional as a result of which various areas became inaccessible and were cut-off. 

 First proposals for railways in India were made in Madras in 1832. The first train in India ran from Red Hills to Chintadripet bridge in 1837. It was called Red Hill Railway and used a rotary steam locomotive manufactured by William Avery.

The first passenger train in India ran between Bombay (Bori Bunder) and Thane on 16 April 1853. The 14-carriage train was hauled by three steam locomotives: Sahib, Sindh and Sultan.

The British introduced the railway system in India because they felt the need for a fast and quick transportation to carry the raw materials across the country easily which was needed by them.  Railways led to increased agricultural output, export of food-grains, widening of markets, commercialization of agriculture, and, hence, cropping pattern. As railways widened the markets for the agricultural sectors, Indian agriculture became linked to the world trade cycles.

It has been one of the chief criticisms of the planning. which emphasised the capital intensive industries in place of promoting the labour intensive industries.

The British rule lasted for two centuries before India won its independence in 1947. The sole purpose of the British economic policy was to reduce India into a feeder economy for expansion of Britain’s own modern industrial base. There was virtually no public sector in the Indian economy. 

The first railway line in India was constructed during the rule of Lord Dalhousie.  The first passenger train in India ran between Bombay (Bori Bunder) and Thane on 16 April 1853.The first train started from Bori Bunder in Bombay at 3:35 pm on April 16, 1853 with a 21-gun salute. It had 14 carriages.

Theory of Demographic Transition is a theory that throws light on changes in birth rate and death rate and consequently on the growth rate of population. Along with the economic development, tendencies of birth-rate and death rate are different. Because of it, the growth rate of population is also different.

The first synchronous census in India was held in 1881. Since then, censuses have been undertaken uninterruptedly once every ten year. The 1881 India wide census enumerated the total number of males as 12,99,41,851 and of females as 12,39,49,970 in a total 1881 population of 25,38,91,821.

The process of demographic transition in India is said to have set in sometime in the late 1920s and early 1930s when death rates started declining. 

Prior to 1920, India’s population was in the first stage with very high birth and high death rates. The death rate fluctuated from year to year, and as a consequence, the size of population remained almost stationary. 

The life expectancy in India during the British rule was 32 years. Now it is near about 50-55 minimum.

 Mortality rate is the total number of deaths from a particular cause in 1 year divided by the number of people alive within the population at mid year.  It is usually expressed in units of deaths per 1,000 per year or it could be described as percent dead in a specific period of time.

Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, its current age and other demographic factors including gender. The most commonly used measure is life expectancy at birth (LEB), which can be defined in two ways.

Water borne diseases like diarrhoea,cholera, air borne diseases  like influenza, chicken pox,mumps,measels ,tuberculosis etc.and inadequate stock,availability and untimely supply medical services are the main causes of high mortality rate.

Infant mortality is the death of young children under the age of 1. This death toll is measured by the infant mortality rate, which is the number of deaths of children under one year of age per 1000 live births 

Infant mortality rate  is the number of deaths per 1,000 live births of children under one year of age. The rate for a given region is the number of children dying under one year of age, divided by the number of live births during the year, multiplied by 1,000

When the British rule ended in India in the year 1947 the literacy rate was just 16%. Over the years, India has changed socially, economically, and globally. After the 2011 census, literacy rate India 2011 was found to be 74.04%.

India's female literacy rate was 7% during 1941.

Average Life Expectancy in India as per the National Health Profile  of Indians is 68.35 years.

India had a strong and bitter colonial experience and a taste of capitalism's exploitative nature. British colonized India to serve as a source of raw material for its fast developing industries. Major Indian states like Tamilnadu, Andhra  pradesh, Maharastra etc. which were highly engaged in agriculture suffered a lot and switched to manufacturing and service sector.

During the British rule, there was some infrastructural development in areas such as roads,  railways, ports, water transport, posts, and telegraphs. But the motive behind this development was simply to foster the colonial interest of the British government. They were never interested in the growth of Indian economy. these infractures like road etc. were used to mobilize the army and carriying out raw materials.

Indeed construction of railways is the biggest contribution to India by the Britishers. Today railway is known as the "life line "of our country . Indian Railways, which had a modest beginning in 1853, has since then been an integral part of the nation. A  network that has held together a population of one billion. A self-propelled social welfare system the Indian Railways has woven a sub-continent together and brought to life the concept of a united India.

The agricultural sector accounted for the largest share of the workforce which was around 70-75%. The manufacturing and the services sectors accounted for only 10 and 15-20 percent respectively , under the British rule.

India's literacy rate is at 74.04%. Kerala has achieved a literacy rate of 93.91%. Bihar is the least literate state in India, with a literacy of 63.82%.

The agricultural sector accounted for the largest share of the workforce which was around 70-75%. The manufacturing and the services sectors accounted for only 10 and 15-20 percent respectively , under the British rule.

Railways ,the greatest gift left by the colonial power, The British companies that laid down the tracks to take advantage of the immeasurably improved experience of traveling across the vast sub-continent offered by train services,

However, cotton was produced in various parts of the Indian sub-continent and it took days to bring it to the nearest port to transport it to England through ships, the only major means of international communication then. The British then had to build a link from the hinterland to India’s major ports for quicker transport of cotton and other goods as demand soared. This expedited matters for the British to introduce a railway in India.

The large proportion of illiterate females is another reason for the low literacy rate in India. Inequality based on gender differences resulted in female literacy rates being lower at 65 %than that of their male counterparts at 82.

In 1850, the first experimental electric telegraph line was started between Calcutta and Diamond Harbour. In 1851, it was opened for the use of the British East India Company. The Posts and Telegraphs department occupied a small corner of the Public Works Department, at that time.

Lord Dalhousie introduced telegraph in India, The use of telegraph brought spectacular changes in the communication system and helped the British in maintaining law an order. They immediately knew about any outbreak and can deploy their force to control any situation.

The British introduced the telegraph  to maintain law and order in India  because they it's help they  could quickly be informed of where an uprising was taking place and quickly send reinforcements there.

During the British rule, there was some infrastructural development in areas such as roads,  railways, ports, water transport, posts, and telegraphs. But the motive behind this development was simply to foster the colonial interest of the British government. They were never interested in the growth of Indian economy. these infractures like road etc. were used to mobilize the army and carriying out raw materials.

Railways led to increased agricultural output, export of food-grains, widening of markets, commercialization of agriculture, and, hence, cropping pattern. As railways widened the markets for the agricultural sectors, Indian agriculture became linked to the world trade cycles.

The state of infrastructure during the pre-British India was very poor due to lack of proper funds , most of the villages lacked connectivity by pucca roads. However, such roads damaged  misery during monsoons as they became muddy and difficult to traverse .During natural calamities, these roads became non functional as a result of which various areas became inaccessible and were cut-off. 

Railways led to increased agricultural output, export of food-grains, widening of markets, commercialization of agriculture, and, hence, cropping pattern. As railways widened the markets for the agricultural sectors, Indian agriculture became linked to the world trade cycles.

In 1850, the first experimental electric telegraph line was started between Calcutta and Diamond Harbour. In 1851, it was opened for the use of the British East India Company. The Posts and Telegraphs department occupied a small corner of the Public Works Department, at that time.

 According to the census reports of Indian Census 2011, the population of India is 1,210,854,977 with 623, 724, 248 males and 586,469, 174 females.

According to the census reports of Indian Census 2011, the population of India is 1,210,854,977 with 623, 724, 248 males and 586,469, 174 females

As per the 2011 Census, the population density of India in terms of number of persons per square km had reached 382 persons per sq km as compared to 325 persons per sq km in the 2001 Census.

According to the census reports of Indian Census 2011, the population of India is 1,210,854,977 with 623, 724, 248 males and 586,469, 174 females

Arunachal Pradesh with the population density of 17 person per square kilometer is the least populated Indian State.

The population density of India in 2011 was 382 per sq km. The rate of increase in density of India has exhibited a sharp decline during 2001- 2011 (17.5 per cent) as compared to 1991-2001 (21.7 per cent).

The literacy rate of India in 2011 is 74.0 per cent.  Literacy rate among females is 65.5 per cent whereas the literacy rate among  males is 82.1 percent

As per 2011 census, Kerala has the highest sex ratio in India with 1084 females per 1000 males

Kerala is the most literate state in India, with 93.91% literacy.

As per consensus of India 2011, the population of India is 1,210,193,422. According to the numbers, Uttar Pradesh is the most populous state with 199,812,341 people.

The literacy rate of India in 2011 is 74.0 per cent.  Literacy rate among females is 65.5 per cent whereas the literacy rate among  males is 82.14 percent

Bihar is the least literate state in India, with a literacy of 63.82%

Sex ratio is defined as the number of females /1000 males. As per census 2011 India has the literacy of 74.04 and sex ratio at the 940females/1000 males.

As per consensus of India 2011, the population of India is 1,210,193,422. According to the numbers, Lakshadweep  is least populous  with 64,473 people of which male and female are 33,123 and 31,350 respectively.

National population policy aims at reduction of infant mortality rate  to below 30 per 1000 live births. Reduce maternal mortality ratio to below 100 per 100,000 live births. Achieve universal Immunization of children against all vaccine preventable diseases.

Demography is the statistical study of populations, especially human beings. Demography encompasses the study of the size, structure, and distribution of these populations, and spatial or temporal changes in them in response to birth, migration, ageing, and death.

The National Population Policy 2000 released on Feb. 15  aims to bring the total fertility rate (TFR) to replacement level by 2010 and to achieve a stable population by 2045, at a level consistent with sustainable economic growth, social development, and environmental protection.

The theory of demographic transition or of population stages or of population cycle has many versions. It has been propounded by W.S. Thomson and F.W. Notestein. They explain the theory in three stages.

Quick Mail service is converted to speed post nowadays. We  have to personally take the letter and hand over in the office. They charge some extra charge than normal post and give us a receipt. It is supposed to reach the destination faster. Quick Mail Service was introduced in India in 1975.

 It was Lord William Bentinck's 1837 act which had introduced Post offices in India. It created the position Director General of post for the whole country.

With 1,55,015 post offices, India Post has the most widely distributed and the largest postal network in the world. The country has been divided into 23 postal circles, each circle headed by a Chief Postmaster General.

The theory of demographic transition or of population stages or of population cycle has many versions. It has been propounded by W.S. Thomson and F.W. Notestein. They explain the theory in three stages of population growth.

The year 1921 is called "The Great Divide" in India because the time India has "Low rate of mortality and High rate birth". Because of famine, there was a serious condition. 1911 to 1921 period decreasing the population due to incurable diseases. The census year 1911- 1921 registered a negative growth rate of-0.31 per cent which happened only once throughout the demographic history of India.

The sex ratio in the country has always remained unfavourable to females. Among Indian states, Kerala has the highest sex ratio of 1084 females to 1000 males.

It is defined as the number of persons per square kilometer. The population density of India in 2001 was 324 persons per square kilometre, which means that now 57 more people live in a square kilometer area in the country than the number that lived a decade ago.

Death rate was 27.4 in 1951, it declined to 7.5  in 2010.

Birth rate was 39.9 in 1951, it fell to 22.1 in 2010.

The first and foremost component of gender statistics revealed by Census 2001, 532 million constituting 52 percent are males and 497 million constituting remaining 48 percent are females in the population. In sheer numbers, males outnumber females by 35 million in population.

India's population recorded the maximum growth rate of $2.22\%$ per annum during the decade $1971 - 81$.