Explore topic-wise InterviewSolutions in Current Affairs.

i. A dead person was buried either in the house or in the courtyard with the idea that the person’s bond with the family should not get cut off even after death. 

ii. Families would also bury various articles with the dead person for them to use even after death.

1. The houses at the beginning of the New Stone Age were made of wattle and daub i.e. the walls were screens woven from sticks or bamboo and plastered with mud or cow dog.

2. Later when the population in the village ettlement grew, people began to build quadrangular” houses of sun-dried bricks. These houses were also bigger and had more than one room. 

3. Regional differences are seen in the styles of constructing houses, depending on the local climate.

1. When the farmers in the village-settlements 

2. produced surplus food, they felt the need for skilled craftsmen who would provide them with agricultural implements and also repair them. 

3. Such craftsmen were paid in the form of food grains or other articles. The craftsmen also purchased the required raw material in the form of foodgrains and other useful articles. 

4. Thus, buying and selling by exchanging goods for goods called barter system was established.

Women are credited to have started cultivation

1. The village community made rules for mutual co-operation in order to keep trade running smoothly. 

2. People responsible for the implementation of these rules became the chiefs of village settlements 

3. These chiefs were also entrusted with the protection of the village. 

4. This is how the village administrative system came into being.

1. Essential things like sharing of agricultural tasks and water resources and the security of the village-settlement gained importance. 

2. People in the village-settlements established some rules and customs to manage these things. 

3. Thus, a social system based on agriculture came into existence.

Poetry is something so intimate and essential that it cannot be defined without oversimplifying it.

The idea of separateness refers to the illusion that human beings and nature are different entities. Secondly, the Earth/nature is dead matter and human beings have the capacity to conquer nature, subdue her, and shake her to her foundations. This idea was popularized by Francis Bacon and other leaders of the scientific revolution. Further, it triggered many scientific experiments which culminated in new inventions and discoveries. These scientific inventions and discoveries served as the basis for the industrial revolution. Cormac Cullinan, a South African environmentalist, calls it ‘eco-apartheid’ and urges us to overcome it just like the apartheid in South Africa.

They used pointed sticks to sow seeds.

Alifano asked Borges what was his first literary reading. Borges replied that his first reading was Grimm’s Fairy Tales in an English version. Alifano further asked him where he had read it. Borges replied that he had read it in his father’s library. He added that it taught him more than any high school would.

The process of bouncing back of light rays in the same medium after hitting the surface of an object is called reflection.

Objects are visible only when light falls on the objects and bounces back to the eye.

In Mendeleev’s periodic table, the difference between atomic masses of two consecutive elements is not the same (⁵²Cr and ⁵⁵Mn). Moseley found out the atomic number of the elements. The atomic number of any element is increased by one unit (number) from the atomic number of subsequent element. \(^{52}_{24}Cr\rightarrow\,^{55}_{25}Mn\) that means in between two elements (Cr aind Mn), element with mass 53 or 54 do not exist.

In Mendeleev’s periodic table, the difference between atomic masses of two consecutive elements is not the same ³⁵Cl and ³⁵Cl. Moseley found out the atomic number of the elements. The atomic number of any element is increased by one unit (number) from the atomic number of subsequent element.

Isotopes \(^{35}_{17}Cl\) and \(^{37}_{17}Cl\) occupy the same position in the modern periodic table. Both isotopes have the same atomic number.

In the modern periodic table, the elements are arranged in the order of their increasing atomic numbers, that the problem of discrepancy in the pairs of isotopes elements observed in Mendeleev’s periodic table was solved. The isotopes of  \(^{35}_{17}Cl\) and \(^{37}_{17}Cl\) were placed in the same group as both have the same atomic number.

The point where rays converge or the point from which rays seem emanate is called focal point (or) focus.

Focal length.

B) moves away from the principal axis

The magnifying lense, telescope, microscope

The rays are diverging and they produced the parallel from the device after refraction. So the device is concave lens

It will be undeviated

A) moves towards the principal axis

A ray will bend towards the normal when it travels from rarer to denser medium and bends away from the normal when it travels from denser to a rarer medium.

PCl₅ → PCl₃ + Cl₂

2BrCl(g) ⇌ Br₂(g) + Cl₂(g), K_C = 5 

10^-3 < K_C < 10³ 

Both forward and backward reaction make significant progress. Neither forward nor reverse reaction predominates.

H₂(g) - CI₂(g) ⇌ 2HCl(g) at 300 K

K₂ = 4 x 10³¹ 

K_C > 10³ 

So [products] >> [Reactant] 

Reaction nearly goes to completion. So forward reaction is favoured.

H₂(g) + I₂(g) ⇌ 2HI(g) at 700 K 

K_C = 57.0 

10^-3 < K_C < 10³

So both forward and backward reaction make significant progress. Neither forward nor reverse reaction predominates.

By amalgamating sodium.

LiI +KF ------>LiF +KI;Larger cation stabilizes larger anion. App

Peptisation:- It is observed that freshly precipitated substances can often be redispersed into colloidal state by suitable reagents, generally with an ion in common with the material to be dispersed. Thus fresh precipitate of Re(OH)₃ readily passes into colloidal form when treated with dil. FeCl₃ solution.

This process of transferrin back a precipitate into colloidal state is called Peptisation.

The ferric chloride which has caused the dispersion is known as Peptising Agent.

It the converse of coagulation and may be regarded as redispersion of coagulation sol.

Coagulation:- The colloidal particle carry similar type of charge and thus due to mutual electrical repulsions are kept apart. But if this charge be somehow neutralized, the particles will come together to form large particles and hence precipitate out.

"This precipitation of colloidal solution is known as Coagulation or Flocoulation."

For example:- An addition of little barium chloride to a colloidal solution As₂S₃ the latter precipitates out. It is due to the fact that +vely charged Ba⁺⁺ ions are attracted by -vely charged particles of As₂S₃ with the result that the charged of the latter gets neutralized. Thus robbed or their charge, the As₂S₃ particles gather together to form bigger aggregates and finally settle down in the form of a precipitate.

Cataphoresis or Electrophoresis:- The particles of colloidal solution are electrically charged either +ve or -ve and hence when and electric current is passed through colloidal solution, the colloidal particles move towards opposite electrodes. On reaching the electrodes they get discharged and precipitate out. Thus a negatively charges sol like that of AS₂S₃ when taken in a U-tube the colloidal particles move towards +ve electrodes while positively charged sol. like that of Fe(OH)₃ when taken in a U-tube the sol. particles move towards -ve electrode.

"This movement of colloidal particle in electric field is known as Cataphoresis."

Cancer starts in our cells. Cells are tiny building blocks that make up the body’s organs and tissues. Cells receive signals from the body, telling them when to grow and when to divide to make new cells. This is how our bodies grow and heal. These cells can become old, damaged or no longer needed. When this happens, the cell gets a signal from the body to stop working and die.

Types of cancer:

Carcinoma – cancer that begins in the skin or in tissues that line or cover internal organs. There are different subtypes, including adenocarcinoma, basal cell carcinoma, squamous cell carcinoma and transitional cell carcinoma.

Sarcoma – cancer that begins in the connective or supportive tissues such as bone, cartilage, fat, muscle or blood vessels. 

Leukaemia – cancer that starts in blood forming tissue such as the bone marrow and causes abnormal blood cells to be produced and go into the blood.

F = 100 dyne = [MLT^-2]

V = 10 cm s^-1 = [LT^-1]

E = 400 ergs = [ML²T^-2]

L = [ML²T^-2]/[MLT^-2] = [E]/[F]

= 400/100

L = 4 cm

[LT^-1] = 10

⇒ 4T^-1 = 10

⇒ T = 0.4 sec

[MLT^-2] = 100

⇒ M 4 × (0.4)^-2 = 100

⇒ M = 4 gm

Answer is (B) enantiomers

C. Both A and B

Correct Answer is: (B) Enantiomer 

Enantiomer, also known as optical isomers, are two stereoisomer that are related to each other by a reflection: they are mirror images of each other that are non-superposable

Correct Answer is: C. Both A and B. 

Correct Answer is: (A) Phosgene 

Chloroform vapour slowly reacts with oxygen in the presence of light to generate phosgene, a highly toxic gas with a smell similar to freshly-cut grass.

C. Both A and B

C - I bond is much weaker than C - Cl bond. Therefore, when CHI₃ is heated it gives I^- ions which give a yellow precipitate of AgI when treated with AgNO₃ solution. On the other hand C - Cl bond of CHCl₃ does not break on heating to give Cl^- ions and hence precipitate of AgCl is not formed when treated with AgNO₃ solution.

The correct option is D) -12.

Here Magnification "M" = 3 

u= -8 cm as u (object distance) is always negative. 

M = -v/u 

3 = -v/-8 

3 = v/8 

v (position of image)= 24 cm 

The image is formed in front of the mirror. 

By using lens mirror formula, focal length can be calculated. 

For focal length: 

1/f = 1/u +1/v 

1/f = 1/-8 + 1/24 

1/f = 1/24 - 1/8 

1/f =1/24 - 3/24 

1/f = -2/24 = -1/12 

f= -12 cm 

Hence the focal length of the lens is - 12 cm.

Spermatogenesis 

1. It occurs inside testis

2. All stages are completed inside testis.

3. It is a continuous process.

4. Spermatogonia develop from germinal epithelium lining the seminiferous tubules.

5. Some cells of the germinal epithelium function as support , also called sertoli cells.

6. All the spermatogonia divide to form spermatocytes.

7. Growth phase is short.

8. Primary spermatocyte divides by meiosis I to form two secondary spermatocytes.

9. Secondary spermatocyte divides by meiosis II to produce two spermatids.

10. A spermatocyte forms four spermatozoa.

11. Sperms are smaller than spermatocytes.

12. Nucleus undergoes condensation in the sperm.

13. Reserve food is little in the sperms.

14.It produces motile male gametes.

Oogenesis

1. It occurs inside ovary.

2. Major part of oogenesis occurs inside ovary but last stages occur inside oviduct.

3. It is discontinuous process with early stages taking place in foetus and the rest later in life.

4. Oogonia develop from germinal epithelium overlying the ovary.

5. There is no such differentiation.

6. Only some oogoinia give rise to oocytes.

7. Growth phase is prolonged.

8. Primary oocyte undergoes meiosis I to form one secondary oocyte and one polar body

9. Secondary oocyte divides by meiosis II to form one ovum and one polar body.

10. A oocyte forms only one egg or ovum.

11. Eggs are larger than oocytes.

12. Nucleus remains uncondensed in the ovum.

13. Ovum collects a lot of reserve food and other biochemicals.

14. It forms non motile female gametes.

Correct Answer is: B. Arsenic 

Examples of heavy metals include lead, mercury, cadmium, sometimes chromium. Less commonly, metals including iron, copper, zinc, aluminum, beryllium, cobalt, manganese and arsenic may be considered heavy metals.

The correct option is B) Double.

As we know that the formula of fringe width is given as

ω = λL/d

Here we know that 

d = distance between two slits 

L = distance of slits from the screen 

λ = wavelength of the light 

Now from above formula we can see that the fringe width is directly depending on the wavelength of light 

So here if the wavelength of light is double then the fringe width must be double of initial value. 

Convex lens 

The object must be withing the focus of the lens.

(B) NO₂ and SO₂

The Correct option is A. SO₂

Cu:

(i) Cuprite - Cu₂O

(ii) Copper pyrites - CuFeS₂

Due to smaller size of F as compared to Cl, steric repulsions will be less in SiF₆^2- than in SiCl₆^2-. Because of smaller S-F bond as compared to S-Cl bond, the interaction of F lone pair of electrons with Si is stronger than that of Cl lone pairs.