Tetravalency: Carbon has a valency of four, so it is capable of bonding with four other atoms of carbon or atoms of some other monovalent element.

Tetravalency:

Carbon has a valency of four, so it is capable of bonding with four other atoms of carbon or atoms of some other monovalent element.

This is known as tetravalency of carbon.

The Human Development Index (HDI) is a single index measure that aims to record the three key dimensions of human development: access to knowledge, a decent standard of living, and long and healthy life. In other words, the human development index is practiced to measure how development has improved human life.

Human Development Index Rank

• India has been on 130^th rank in Human Development Index.

Life Expectancy

• It is the age which a particular person belonging to a particular age is expected to live.
• Life Expectancy at birth in IndiaMales: 67.34 years

  Females: 69.64 years

Infant Mortality Rate

• It is the total number of infants dying below the age of 1 year out of 1000 babies.
• Infant Mortality Rate in India is 40.5 infants.

he molar masses of all these substances will be equal to the respective molecular masses expressed in g / mol . Now :

(a) Molar mass of ethyne, C2H2 = Mass of C × 2 + Mass of H × 2

= 12 × 2 + 1 × 2

= 24 + 2

= 26 g / mol

(b) Molar mass of sulphur molecule, S8 = Mass of S × 8

= 32 × 8

= 256 g/ mol
 

परिचय

केवल एक लड़की होने की वजह से उसका समय पूरा होने के पहले ही कोख़ में एक बालिका भ्रूण को खत्म करना ही कन्या भ्रूण हत्या है।

आंकड़ों के अनुसार, ऐसा पाया गया है कि पुरुष और महिला लिंगानुपात 1961 में 102.4 पुरुष पर 100 महिला, 1981 में 104.1 पुरुषों पर 100 महिला, 2001 में 107.8 पुरुषों पर 100 महिला और 2011 में 108.8 पुरुषों पर 100 महिला हैं। ये दिखाता है कि पुरुष का अनुपात हर बार नियमित तौर पर बढ़ रहा है। भारत में वहन करने योग्य अल्ट्रासाउंड तकनीक के आने के साथ ही लगभग 1990 के प्रारंभ में ही कन्या भ्रूण हत्या शुरुआत हो चुकी थी।

भारत में 1979 में अल्ट्रासाउंड तकनीक की प्रगति आयी हालांकि इसका फैलाव बहुत धीमे था। लेकिन वर्ष 2000 में व्यापक रुप से फैलने लगा। इसका आंकलन किया गया कि 1990 से, लड़की होने की वजह से 10 मिलीयन से ज्यादा कन्या भ्रूणों का गर्भपात हो चुका है। हम देख सकते हैं कि इतिहास और सांस्कृतिक पृष्ठभूमि के द्वारा कन्या भ्रूण हत्या किया जा रहा है। पूर्व में, लोग मानते हैं कि बालक शिशु अधिक श्रेष्ठ होता है क्योंकि वो भविष्य में परिवार के वंश को आगे बढ़ाने के साथ ही हस्तचालित श्रम भी उपलब्ध करायेगा। पुत्र को परिवार की संपत्ति के रुप में देखा जाता है जबकि पुत्री को जिम्मेदारी के रुप में माना जाता है।

प्रचीन समय से ही भारतीय समाज में लड़कियों को लड़कों से कम सम्मान और महत्व दिया जाता है। शिक्षा, स्वास्थ्य, पोषण, खेल आदि क्षेत्रों में लड़कों की तरह इनकी पहुँच नहीं होती है। लिंग चयनात्मक गर्भपात से लड़ने के लिये, लोगों के बीच में अत्यधिक जागरुकता की जरुरत है। “बेटियाँ अनमोल होती हैं” के अपने पहले ही भाग के द्वारा आम लोगों के बीच जागरुकता बढ़ाने के लिये टी.वी पर आमिर खान के द्वारा चलाये गये एक प्रसिद्ध कार्यक्रम ‘सत्यमेव जयते’ ने कमाल का काम किया है। जागरुकता कार्यक्रम के माध्यम से बताने के लिये इस मुद्दे पर सांस्कृतिक हस्तक्षेप की जरुरत है। लड़कियों के अधिकार के संदर्भ में हाल के जागरुकता कार्यक्रम जैसे बेटी बचाओ बेटी पढ़ाओं या बालिका सुरक्षा अभियान आदि बनाये गये हैं।

महिलाओं को भारतीय समाज में अपने परिवार और समाज के लिये एक अभिशाप के रुप में देखा जाता है। इन कारणों से, तकनीकी उन्नति के समय से ही भारत में बहुत वर्षों से कन्या भ्रूण हत्या की प्रथा चल रही है। 2001 के सेंसस के आंकड़ों के अनुसार, पुरुष और स्त्री अनुपात 1000 से 927 है। कुछ वर्ष पहले, लगभग सभी जोड़े जन्म से पहले शिशु के लिंग को जानने के लिये लिंग निर्धारण जाँच का इस्तेमाल करते थे। और लिंग के लड़की होने पर गर्भपात निश्चित होता था।

भारतीय समाज के लोग लड़के से पूर्व सभी बच्चियों को मारने के द्वारा लड़का प्राप्त करने तक लगातार बच्चे पैदा करने के आदी थे। जनसंख्या नियंत्रण और कन्या भ्रूण हत्या को रोकने के लिये, कन्या भ्रूण हत्या और लिंग निर्धारण जाँच के बाद गर्भपात की प्रथा के खिलाफ भारतीय सरकार ने विभिन्न नियम और नियमन बनाये। गर्भपात के द्वारा बच्चियों की हत्या पूरे देश में एक अपराध है। चिकित्सों द्वारा यदि लिंग परीक्षण और गर्भपात कराते पाया जाता है, खासतौर से बच्चियों की हत्या की जाती है तो वो अपराधी होंगे साथ ही उनका लाइसेंस रद्द कर दिया जाता है। कन्या भ्रूण हत्या से निज़ात पाने के लिये समाज में लड़कियों की महत्ता के बारे में जागरुकता फैलाना एक मुख्य हथियार है।

The human face has 14 bones. The following are the names of these 14 bones:- 

Inferior nasal concha (2), 

Lacrimal bones (2), 

Mandible (1), 

Maxilla (2), 

Nasal bones (2), 

Palatine bones (2), 

Vomer (1), 

Zygomatic bones (2).

1)C

2)A

3)C

4)D

5)A

Answer:

Use the pythagoras theorem.

Step-by-step explanation:

Check the figure.

The length of the standing part of the tree = 15 m

Length of the base = 20 m

To find: Hypotenuse or the longest side.

Using Pythagoras theorem,

Where, ab = 15 m

bc = 20

225 + 400 = 

625 = 

 = ac

∴ ac = 25

Answer:  The two occupations one can choose after being trained in the area of child development are:

(i) Open a creche.

(ii) Aanganwadi worker under ICDS(integrated Child Development Services project).

approx 8 minutes

Sunlight travels at the speed of light. Photons emitted from the surface of the Sun need to travel across the vacuum of space to reach our eyes. The short answer is that it takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth

The four symmetrical objects are black board, the table top, a pair of scissors, the computer disc etc.

Step's of construction

(1) Draw BC = 6 cm.

(2) Construct  ∠CBX = 60°.

(3) Along BX , set off BP = 9 cm.

(4) Join CP

(5) Draw the perpendicular bisector of CP tp intersect BP at A .

(6) Join AC. Then, ∆ABC is the required triangle.

Material culture refers to the physical objects, resources, and spaces that people use to define their culture. These include homes, neighborhoods, cities, schools, churches, synagogues, temples, mosques, offices, factories and plants, tools, means of production, goods and products, stores, and so forth. All of these physical aspects of a culture help to define its members' behaviors and perceptions. For example, technology is a vital aspect of material culture in today's United States. American students must learn to use computers to survive in college and business, in contrast to young adults in the Yanomamo society in the Amazon who must learn to build weapons and hunt.

Altruism: The principle of acting to benefit others without any selfishness or self-interest.

Sociologists understand altruism as a 'principle of unselfish regard for the needs and interests of others'. Durkheim studied some forms of suicide a category of altruistic sacrifice some individuals make for their societies in particular contexts, whether it be due to a strong sense of social cohesion or tradition.

Division of labour refers to the method of organising production where the work required to produce a product is divided into different specialized tasks with different workers specializing in each task.
The four ways in which division of labour will influence production in an economy are as follows:
i. Quality of production improves - Division of labour leads to an increase in the efficiency of labour which further leads not only to an increase in the quantity of output but also to an improvement in the quality of the produced goods and services.
ii. Large scale production - Division of labour makes large scale production possible. Indeed, scale production requires division of labour. If a car manufacturing company, for instance wishes to make 10000 cars in a year but does not introduce division of labour in its factory, it will have to employ so many workers that it will not be an economically viable company. It is by virtue of division of labour that the company can produce 10000 cars per year with a reasonable number of workers.
iii. Reduced average cost - Since division of labour increases total output, even with an unchanged number of labourers, the average cost of producing a commodity falls. This is a social advantage. Society can produce goods by incurring lower average cost of production.
iv. Lower prices of output - The reduced average cost of the products leads to reduced prices of the outputs in the market. As a result, consumers are benefitted.

Divisin of Labour :

1. It means labour will be distributed among the different individuals having different skills of specializations.

2. Division of labour became popular in modern and complex societies after the Industrial Revolution.

3. With the increase of division of labour in modern societies, individuals are more than ever functionally connected by their mutual needs.

4. Due to this process, every labour (usually) is specialised, individuals become more dependent on others to perform separate economic functions, which they are not able to carry out themselves

1. Face-to-face interaction: Primary groups are characterized by close intimate and face to face interaction.
2. Intimacy: Here everyone knows everyone else and there is strong intimacy among the members. They are even known to nick names of their members.
3. Mutual Aid & Help: Mutual aid assistance among the members of the groups always found. They cooperate with each other at the time of help.
4. Consciousness of kind: Consciousness of kind exists. If means they recognize one another and express it whenever needed.
5. We – Feeling: we – feeling (sense of unity and commonality) is found among the members of the group. It means they live together as one body.
6. Small in Size: Primary groups are smaller in size. Large number decreases intimacy and loose the bond of the group.
7. Physical proximity or nearness: face-to-face relation can be found only when members live in a particular area more or less on permanent basis.
8. Frequent Interaction: Interaction among members of the group is frequent and it can be many times in a day.
9. Personal relation: In this, interest of each is centered in others as persons. They interact with each other on the basis of personal relation.
10. Similarity of background: Members must have more or less similar background.

The classes were: 

1. Feudal Classes: The king stood at the top. He bestowed lands to a number of lords. These lords distributed lands to lesser lords called barons. The Dukes and Earls were king’s Vassals. They showed allegiance to the king.

In the time of war, the king could demand military help from his Vassals. The feudal lords kept soldiers. They levied taxes.

2. The peasants: The peasants formed the lowest class. Their number was largest in society. The peasants were divided into many classes -freeholders and villeins.

A new class sprang up. It was the middle class. Reasons for its development was the coming of new inventions and development of trade and industries.

• A society is a group of people who share a common culture, occupy a territorial area and are bound to each other by a common history.
• Societies may be simple, may be complex. It is natural to human beings. We all are social beings. We cannot survive without society. We human beings cannot attain our goals alone, we want society. The society provides us security, relationship, identity and sense of belonging ness.
• Society is mandatory not only for mere survival but also for a good life.
• Society is a continuous process. It is not imposed upon people. It goes on as a natural process. Social relations are the base of social structure. Society can be understood in its abstract as well as concrete form.

The viscous force acting on a sphere is directly proportional to the following parameters:

• the radius of the sphere
• coefficient of viscosity
• the velocity of the object

Mathematically, this is represented as

F∝ηarbvc

Now let us evaluate the values of a, b and c.

Substituting the proportionality sign with an equality sign, we get

F=kηarbvc (1)

Here, k is the constant of proportionality which is a numerical value and has no dimensions.

Writing the dimensions of parameters on either side of equation (1), we get

[MLT^–2] = [ML^–1T^–1]^a [L]^b [LT^-1]^c

Simplifying the above equation, we get

[MLT^–2] = M^a ⋅ L^–a+b+c ⋅ T^–a–c (2)

According to <a href="https://byjus.com/physics/mechanics/">classical mechanics</a>, mass, length and time are independent entities.

Equating the superscripts of mass, length and time respectively from equation (2), we get

a = 1 (3)

–a + b + c = 1 (4)

–a –c = 2 or a + c = 2 (5)

Substituting (3) in (5), we get

1 + c = 2

c = 1 (6)

Substituting the value of (3) & (6) in (4), we get

–1 + b + 1 = 1

b = 1 (7)

Substituting the value of (3), (6) and (7) in (1), we get

F=kηrv

The value of k for a spherical body was experimentally obtained as 6π

Therefore, the viscous force on a spherical body falling through a liquid is given by the equation

F=6πηrv