Explore topic-wise InterviewSolutions in Current Affairs.

i. Copper metal in the first transition series exhibits +1 oxidation state most frequently.

ii. Copper has electronic configuration [Ar] 3d¹⁰ 4s¹ . It can easily lose one (4s¹) electron to give stable 3d¹⁰ configuration. Hence, it exhibits +1 oxidation state most frequently.

Let the woman’s present age be x years.

Let her daughter’s present age be y years. 

Then, we have: 

x = 3y + 3 

⇒ x – 3y = 3 …….(i) 

After three years, we have: 

(x + 3) = 2(y + 3) + 10 

⇒ x + 3 = 2y + 6 + 10 

⇒ x – 2y = 13 ……(ii) 

Subtracting (ii) from (i), we get: 

-y = (3 – 13) = -10 

⇒ y = 10 

On substituting y = 10 in (i), we get: 

x – 3 × 10 = 3 

⇒ x – 30 = 3 

⇒ x = (3 + 30) = 33 

Hence, the woman’s present age is 33 years and her daughter’s present age is 10 years.

Non-Cooperation Movement began in December 1920. It spread to the countryside in the following ways. 

• The movement started with the participation of middle-class in the cities. Thousands of students left the government-controlled schools and colleges, teachers resigned and lawyers gave up their practice. It was to be a nonviolent movement. 
• In Awadh, peasants were led by Baba Ramchandra. Here, the movement was against talukdars, who charged high rents and peasants had to do beggar. 
• The peasant movement demanded reduction of revenue and abolition of beggar. By the end of 1920, Jawaharlal Nehru, Baba Ramchandra and others had formed Oudh Kisan Sabha. So after the beginning of the Non- Cooperation. Movement, Congress wanted to integrate the Awadh peasants struggle into a wider struggle. 
• Tribal peasants interpreted the message of Gandhiji and idea of swaraj in their own way. In Gudem Hills in Andhra Pradesh, a militant guerrilla movement was organised against colonial oppression under the leadership of Alluri Sitaram Raju. He was inspired by the NonCooperation Movement. 
• The Gudem rebels attacked police stations, attempted to kill British officials and carried on guerrilla warfare for achieving swaraj. 
• The movement also spread among the plantation workers in Assam. They were not permitted to leave the tea gardens without permission.

Spraying water is not a good way of putting out an oil fire or an electrical fire. If water is sprayed onto an oil fire, the oil will •float to the top of the water and continue to burn. This can be very dangerous because water can flow quickly carrying the burning oil with it and spreading the fire. Similarly, the person spraying water on an electrical fire might receive an electric shock and be killed.

Fire can be put out by taking away the fuel, stopping the supply of oxygen or by removing the heat from the fuel. These are the three main ways to put out fire.

Fire can be put out by taking away the fuel, stopping the supply of oxygen or by removing the heat from the fuel. These are the three main ways to put out fire.

We cannot use water in case of oil and electric fires. Oil floats over water and thus oil fires cannot be extinguished using water. Water flows on and it has the risk of s spreading the fire along. In case of electric fires water cannot be used as an extinguisher, It being a good conductor of electricity, puts the life of the man spraying it in danger.

(1) Fire is the result of a chemical reaction. When the oxygen in the air combines with carbon and hydrogen in a fuel, a chemical reaction takes place.

(2) Oxygen is very much available any time because it stays in air.

(3) Fuel and oxygen do not make fire by themselves. Fire requires three things all together to make it; they are fuel, oxygen and heat (fire). Absence of any one of these three fail to make a fire. If fire can be made without heat, everything in open will catch fire soon as fuel and oxygen are already available in open.

Oxygen is one of the three elements s essential for causing fire. If we can disrupt s the supply of oxygen then we can put out the fire. This can be applied in case of small fires. If we throw a damp blanket or a sack over the fire, it cuts off the supply of oxygen and the fire is immediately put out.

(c) Hermithood and retirement – Vanaprasthashram

(b) Rulers and warriors – Kshatriya

The three intellectuals who calculated national income of India before independence were Findley Shiraj, Dr. V.K.R.V. Rao, and R.C. Desai.

If fire goes out of control, It can cause damage to our life, house and property. It is ‘bad master’ in this sense.

(i) A (4) B (2) C (3) D (1)

(i) A (3) B (4) C (2) D (1)

(ii) A (4) B (3) C (1) D (2)

Fire is used in cooking, to keep our homes warm during winter. Fire is also used to produce electricity.

(i) A (2) B (3) C (4) D (1)

Every fuel catches fire at a particular temperature. This temperature is called the ‘flash point’ of a fuel.

Correct option is (iv ) (ii) (iii) (i)

For survival, an individual needs energy which it obtains from life processes such as nutrition and respiration. Reproduction does not provide energy for survival. Instead, reproduction ensures transfer of genetic material from one generation to the next which helps in continuation of species. Hence, it is an important phenomenon for maintaining continuity of species.

The birth of the fully developed foetus (childbirth) is called parturition.

The period of development of foetus in the uterus till birth is called gestation. It is of 9 months duration (i.e., 280 days or 40 weeks from the first day of the last menstrual cycle) in human beings.

The lining of uterus becomes thick for nourishing the embryo if fertilisation takes place and egg reaches the uterus.

Smokers percentage in Andhra Pradesh 68%

A) Adam’s apple

Larynx: It is a part of the human respiratory system. It is generally called the ‘voice box It has vocal cords that vibrate during expiration and produce sounds.

The number of cartilage present in Larynx 9.

‘X’ is more reactive than ‘Y’ because it displaces ‘Y’ from its salt solution.

(a) It is because it reacts with acids as well as bases to produce salts and water.’Al’ is less electropositive metal. So, it forms amphoteric oxide which can react with acid as well as base. 

(b) Ionic compounds can conduct electricity in molten state because ions ’ become free to move in molten state.

Yes, sodium reacts explosively even with cold water, it is most reactive. Magnesium reacts with hot water, it is less reactive than Na. Iron reacts only with steam which shows it is least reactive among the three.

Carbon is added to the molten iron to improve the properties of iron and it basically enhances the strength, hardness and corrosion resistance property of iron.

(a) Graphite is a greyish-black opaque substance. It is made up of carbon.

(c) Due to the presence of free electrons in a graphite crystal, it conducts electricity however; a diamond crystal does not have free electrons so it does not conduct electricity.

(d) (i) Used as a lubricant (ii) Used for making pencil leads.

Graphite is a greyish-black opaque substance. It is made up of carbon.

(a) Diamond is a colourless transparent substance having extraordinary brilliance. It is made up of carbon.

(c) Diamond has a high melting point because a lot of heat energy is required to break the network of strong covalent bonds in the diamond crystal.

(d) (i) Used in rock drilling equipment (ii) Used in making jewellery.

Diamond is a colourless transparent substance having extraordinary brilliance. It is made up of carbon.

False 

The development of the child inside the mother’s body takes approximately nine months.

Gangue or matrix

Ore is an impure metal containing large amount of sand and rocky material. The impurities like sand, rocky materials, limestone, mica etc present in the ore is called gangue or matrix.

Correct option  (D) lV only

Explanation: 

The reaction is highly exothermic.

(c) placenta

The substance added to the ore to remove the matrix called flux results in the formation of a fusible compound called slag.

Gangue + Flux = Slag.

Correct option  (C) Froth floatation process, conversion to metal oxide and reduction of metal oxide 

Aluminium is extracted from bauxite ore

(a) Cinnabar Mercury is obtained from its ore by roasting.

HgS +O₂ → Hg + SO₂

(b) When aluminium is heated with Fe₂O₃ to get molten iron, it is called thermite reaction.

Fe₂O₃ + 2Al → Al₂O₃ + 2Fe

Molten iron is used to weld broken railway tracks. 

(c) Electrolytic reduction

The naturally occurring chemical substances in form of which the metal occur in the earth along with impurities are called minerals. The minerals from which the metal can be extracted conveniently and economically is called an ore. Thus, all ores are minerals but all minerals are not ores. For example iron is found in the earth’s crust an oxides, carbonates and sulphides. Out of these minerals of iron, the oxides of iron are employed for extraction of the metal. Therefore, oxides of iron are the ores of iron. Similarly, aluminium occurs in earth’s crust in form of two minerals, i.e, bauxite (Al₂O₃. x H₂O) and clay (Al₂O₃.2SiO. 2H₂O). Out of these two minerals, Al can be conveniently and economically extracted from bauxite the ore of aluminium.

The iron obtained from blast furnace is called pig iron. It contains about 4% carbon and many other impurities (eg S, P, Si, Mn) in smaller amounts.

Cast iron, on the other hand, is made by melting pig iron with scrap iron and coke using hot air blast, it has slighly lower carbon content (about 3%) and is extremely hard and brittle.

(a) Ionic bond will be formed; element C donates its electron to element D.

(b) B is an inert gas; has complete octet configuration.

(c) C 2 A; element A needs two electrons to complete its octet.

XY forms ionic bo nd. The electronic configuration of X changes from 2, 8, 2 to 2, 8, it donates its 2 electrons to two Y atoms. Hence, the elec tronic configuration of Y changes f rom 2, 8, 7 to 2, 8, 8 giving the compound XY₂ .