The walls of the classroom had bright and colourful pictures of a horse, a goat, a parrot and a cow. They all looked familiar to Bholi and were like the ones in the village. That is why she was fascinated to see those pictures

Answer: The narrator had hated city life. This ride through the village made him very happy. He was overjoyed to meet the  hack driver. Even he planned to settle down in that village. So he was happy though he had not found Lutkins.

Advancement of international trade of a country is an index to its prosperity:

1. Resources are space-bound so countries need to trade with each other to procure various resources.

 2. When the value of exports exceeds the value of imports, its favourable balance of trade. This shows a positive condition of the economy.

3. When the value of imports exceeds the value of exports, its unfavourable balance of trade. This is negative for an economy.

4. Increased international trade shows increased relations between countries which is mutually beneficially.

 5. International trade is also considered an economic barometer for a country because it's a huge source of income as well as a sign of development.

(i) Railways are the principal mode of transportation for freight and passengers in India, as they link different parts of the country. 

(ii) They carry huge loads and bulky goods to long distances. 

(iii) Railways make it possible to conduct multifarious activities like business, sightseeing, and pilgrimage along with goods transportation over longer distances. 

(iv) Railways have been a great integrating force for the nation, for more than 150 years now. 

(v) They have been helpful in binding the economic life of the country and cultural fusion. 

(vi) They have accelerated the development of the industry and agriculture.

The relationship Between Muslim league and congress saw many upheavals. At times it required cooperation from both while sometimes it stood on complete opposition to each other.

The league -congress relationship had been one of the most controversial issue during the time of Indian Independence.

Both the parties which believed in cooperation and coexistence among the both.

Although the major issue of opposition among the two had been on the question of representation which finally led to partition in the long run.

The period between 1919-20s saw the most harmonious period between the two parties which were never visible in the near future.

Important issue which marked the difference was the Hindu Muslim conflict. Hindus and Muslims the two largest communities living in India entered into pitched political battles as a result of the political developments that captured the Indian freedom struggle.

The differences got more furated with the results of general elections and provincial elections held under the British rule .

As the league failed to gather popular support in comparison to the congress this added to the dissatisfaction.

All this ended up, into loss of innocent lives and division of the subcontinent into two dominion

The relationship Between Muslim league and congress saw many upheavals. At times it required cooperation from both while sometimes it stood on complete opposition to each other.

The league -congress relationship had been one of the most controversial issue during the time of Indian Independence.

Both the parties which believed in cooperation and coexistence among the both.

Although the major issue of opposition among the two had been on the question of representation which finally led to partition in the long run.

The period between 1919-20s saw the most harmonious period between the two parties which were never visible in the near future.

Important issue which marked the difference was the Hindu Muslim conflict. Hindus and Muslims the two largest communities living in India entered into pitched political battles as a result of the political developments that captured the Indian freedom struggle.

The differences got more furated with the results of general elections and provincial elections held under the British rule .

As the league failed to gather popular support in comparison to the congress this added to the dissatisfaction.

All this ended up, into loss of innocent lives and division of the subcontinent into two dominion

Dense and efficient network of transport and communication: 

(i) We use different material and services in our daily life. Some of these are available in our immediate surroundings while other requirements are met by bringing things from other places. Movement of these goods and services can be over three domains of earth. 

(ii) Today, the world has converted into a large village with the help of efficient and fast moving transport. 

(iii) Transport has been able to achieve this with the help of equally developed communication system. 

(iv) Therefore transport, communication and trade are complementary to each other. 

(v) Today India is well linked with the rest of the world despite its vast size diversity, linguistic and socio-cultural plurality.

Four major problems faced by cotton textile mills in India.

1. The yarn in India is produced by small industries and units which largely cater to local markets. Thus, while many spinners export cotton yarn, many garment manufacturers have to import fabric. Therefore, there is a mismatch between the two.

2. Most of the machinery installed in cotton mills are outdated and need to be replaced.

3. Irregular power supply has hampered production.

4. The cotton industry is facing tough competition from the fibre industry. 

Four major problems faced by cotton textile mills in India.

1. The yarn in India is produced by small industries and units which largely cater to local markets. Thus, while many spinners export cotton yarn, many garment manufacturers have to import fabric. Therefore, there is a mismatch between the two.

2. Most of the machinery installed in cotton mills are outdated and need to be replaced.

3. Irregular power supply has hampered production.

4. The cotton industry is facing tough competition from the fibre industry. 

An amphoteric oxide is one that can act as a base or as an acid. The non-metallic oxides are generally acidic and the metallic oxides are basic. Metallic oxides are known as amphoteric oxides which display both the basic and acidic nature. Elements that form amphoteric oxides have some metals and some of the non-metals characteristics. Amphoterism is based upon an oxide’s oxidation state. This oxide reacts with base and acid to produce salt and water as the main products.

Amphoteric oxides react with both acids and alkalis to form salt and water. Examples of amphoteric oxides are zinc oxide and aluminum oxide.

ZnO(s) + 2HCl(aq) →  ZnCl2(aq) + H2O(l)

ZnO(s) + 2NaOH(a) → Na2ZnO2(aq) + H2O(l)

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l)

Al2O3(s) + 2NaOH(aq) → 2NaAlO2(aq) + H2O(l)

(i) When Indian leaders were arrested, angry crowds demonstrated in the streets of Peshawar, facing armoured cars and police firing. Many were killed.
(ii) A month later, when Gandhiji himself was arrested, industrial workers attacked police posts, government buildings, law courts and railway stations and all structures that symbolised the British rule.
(iii) A frightened government responded with a policy of brutal repression. Peaceful satyagrahis were attacked, women and children were beaten, and about 100,000 people were arrested.
(iv) To break the deadline between Congress and the government Lord Irwin invited Gandhiji for a peace pact i.e Gandhi-Irwin pact.
(v) Under such a situation Gandhiji decided to call off the movement.

Let four numbers in A.P. be a – 3d, a – d, a + d and a + 3d.

(a – 3d) + (a – d) + (a + d) + (a + 3d) = 32

⇒ 4a = 32

⇒ a = 8

Product of extremes = (a – 3d) (a + d) + (8 – 3d) (8 + 3d) = 64 – 9d²

Product of means = (a – d) (a + d) = (8 – d) (8 + d) = 64 – d²

Product of extremes: product of means = 7:15  (Given)

When a = 8 and d = 2

a – 3d = 8 – 3 × 2 = 8 – 6 = 2

a – d = 8 – 2 = 6

a + d = 8 + 2 = 10

a + 3d = 8 + 3 × 2 = 8 + 6 = 14

When a = 8, d = –2

a – 3d = 8 – 3 × (–2) = 8 + 6 = 14

a – d = 8 – (–2) = 8 + 2 = 10

a + d = 8 – 2 = 6

a + 3d = 8 + 3 × (–2) = 8 – 6 = 2

∴ The four numbers are 2, 6, 10 and 14.

Let the three terms be a-d,a,a+d

Sum=a-d+a+a+d=48

Solving this, we get

3a=48

a=16

a(a-d)-4(a+d)=12

Keeping the value of a in above equation

16(16-d)-4(16+d)=12

Solving this, we get

d=9

Therefore terms are 7,16,25 (ans)

or

Let the first three terms of the AP be (a-d), a and (a+d). Then,

Hence, the first three terms of the AP are 7, 16, and 25.

The parts are in AP, let the terms be a-d, a and a+d

where the first term =a-d

the common difference =d

Given, sum =24cm

a-d + a+a +d = 24cm

3a = 24cm

a =8cm

Given: Product of the terms = 440

(a-d) (a) (a+d) = 440

(8-d) (8+d) (8) =440

(8-d)(8+d) = 55

8² -d² = 55

64 - d² = 55

d² = 64-55

d² = 9

d = 3 or -3

AP- a-d , a, a+d

so the AP is 8-3, 8, 8+3 or 8+3,8,8-3

AP = 5, 8, 11 or 11, 8, 5

 4 : 3

Let S_n and S'_n be the sums of n terms of two AP’s and T₁₁  and T₁₁ be the respective 11^th terms. Then

Now put n = 21. We get

Note: If ratio of sum of n terms of two APs is given in terms of n and ratio of their p^th terms is to be found then put n = 2p - 1. Here we put n = 11 x 2 - 1 = 21.

Parts of a Electric Motor

• Insulated Copper wire: A rectangular coil of wire ABCD
• Magnet Poles: A magnet as placed above ie North Pole and South Pole. This creates a magnetic field as shown above.
• Split Rings: Two disjoint C-shaped rings P and Q. It acts as a commutator (which can reverse the direction of current)
• Axle: The split rings are placed on the axle which can rotate freely.
• Brushes: The outside of the split rings are connected to conducting brushes X and Y.
• Source Battery: To source current.

Working

• When the current begins to flow, current flows through brush X, then A to B, B to C, C to D and then to brush Y and into the battery.
• Now applying Fleming's Left Hand Rule to wire AB, Current is along AB, Magnetic Field is as shown (North-> South), the motion of the wire is downwards.
• Now applying Fleming's Left Hand Rule to wire CD, Current is along CD, Magnetic Field is as shown (North-> South), the motion of the wire is upwards.
• The rectangular coil begins to move in the anti-clockwise direction
• Note that during anti-clockwise motion, the split rings and axle also move, whereas the brushes don't move.
• After half a rotation, Wire CD and Split ring Q moves to the left.  Wire AB and Split ring P moves to right. Brushes X and Y donot move.
• Now applying Fleming's Left Hand Rule to wire CD, Current is along DC. (Battery -> Split ring Q -> DC , Magnetic Field is as shown (North-> South), the motion of the wire is downwards.
• Now applying Fleming's Left Hand Rule to wire AB, Current is along BA. (Battery -> Split ring Q -> DC --> CB -> BA --> Split ring P) , Magnetic Field is as shown (North-> South), the motion of the wire is upwards.
• So, again the coil rotates in the anti-clockwise direction.
• The reversal of current in the coil results in the continous rotation of the coil. The reversal of current is achieved by the commutator rings

Applications

• Electric Fans
• Refrigerators
• Mixers
• Washing machines

An electric motor is used to convert electrical energy into mechanical energy. Let’s go through an instance: What does the mixer in your house do for you? The rotating blades mash and mix things for you. And if someone were to ask you how that works, what would you say? You would probably say that it works on electricity. Well, that’s not incorrect. Motors convert electric energy to mechanical work. The opposite is done by generators that convert mechanical work to electrical energy.

Different Parts of an Electric Motor and Their Function

A simple motor has the following parts:

• A power supply – mostly DC for a simple motor
• Field Magnet – could be a permanent magnet or an electromagnet
• An Armature or rotor
• Commutator
• Brushes
• Axle

Answer:

The name plaster of Paris came from the fact that it was first of all made by heating gypsum which was mainly found in Paris. The compound plaster of Paris is prepared by heating gypsum at 120^oC.

CaSO₄.2H₂O → CaSO₄.1/2H₂O + 3/2H₂O

The chemical formula for the plaster of Paris is (CaSO₄) H₂O and is better known as calcium sulfate hemihydrate.

Plaster of Paris is a popular substance that is utilized most commonly for sculpting materials and in gauze bandages. While we have seen many applications of this material in our everyday lives if we try to understand its chemistry, plaster of Paris is a white powdery chemical compound which is hydrated calcium sulfate that is usually obtained from calcining gypsum.

Plaster of Paris is also referred to as Gypsum plaster. The chemical formula of plaster of Paris is written as CaSO4·H2O or 2CaSO4·H2O.

(a) Most of the metals do not react with hydrogen. Only a few reactive metals reacts with hydrogen to form metal hybrides. 

     For example: when hydrogen gas is passed over heated sodium, then sodium hybride is formed.

(b) Non metals react with hydrogen to form covalent hybrides. 

     For example sulphur combines with hydrogen to form hydrogen sulphide. 

When a metal reacts with a non-metal few changes takes place with the compound or molecules undergoing in the reaction. Let us see what happens.

Transfer of electrons

When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms, forming ions. The resulting compound is called an ionic compound.

Formation of ions

The metal atoms give electrons to the non-metal atoms. The metal atoms become positive ions and the non-metal atoms become negative ions.

Reactions

Few examples of the reaction between metals and non metals

• Sodium + chlorine → sodium chloride
• Magnesium + oxygen → magnesium oxide
• Calcium + chlorine → calcium chloride

Uses of Sodium Chloride

• It is widely used in food industries as a food preservative and as a flavour enhancer.
• It is a major raw material in the industrial manufacturing of various chemicals such as sodium carbonate, sodium hydrogen carbonate etc.
• This salt is used in glass production.
• In cold countries, it is used to prevent the build-up of ice on roads, bridges etc which is important for safe driving conditions.

Organised sector: All enterprises which are either registered or came under the purview of any of the relevant government rule, like Factory Act.
People enjoy working in the organised sector as there is a proper and systematic way to get the work done from the employees.

Answer:

Valli did not get off from the bus when it was terminated at the bus stand because she had come in the bus just for a ride and would go back in the same bus.

On the way to the town, Valli saw a frightened cow running right in front of the bus. She clapped gleefully as the cow ran faster. Valli did not get off the bus at the town. She did not want to go to the stall and have a drink because she had no money.