Explore topic-wise InterviewSolutions in Current Affairs.

The peer review process can create a conflict of interest because favouritism can be shown. Peers often want to support their friends or those close to them so will choose their projects over others. They are trying to help those they care about to succeed.

Congress proposes an amendment by a two thirds vote in state legislatures ratify the amendment by a three fourths vote.

The Industrial revolution was mixed blessing because of the following reasons:

(i) It brought about the machine system of production where the production output was very high. However, it led to a decline of the traditional artisans, craftsmen in the colonies which served as markets for these products.

(ii) The new factory system of production brought about huge profits for the owners but the working conditions of workers were very poor with no social security, long working hours without rest-periods, child labor and unsafe, unclean work environment.

(iii) The urban landscape grew very fast but the cities were full of slums, squatter settlements, social and moral degradation of the society. The GDP was rising but not the happiness quotient of the working class.

(iv) Capitalism bloomed but it meant profit only for few while the working class was undergoing misery and thus it led torise of Socialism, an international movement for worker solidarity which was against the capitalist mode of production.

(v) It brought revolution in transportation which reduced distances but at the same time, the pollution levels too began to increase. Indeed since Industrial revolution, the CO2 added has increased manifolds and its negative impacts have begun to appear as climate change.

Thus, industrial revolution had some disadvantages but largely, it was an event which changed the course of history with new modes of production, new political systems, ideologies, discoveries and inventions.

Herbivores have longer intestines than carnivores to digest grass. These intestines have many small bacteria that processes and breaks down cellulose into glucose, a source of energy that the host herbivore can use. Without these long intestines, animals such as cows could still eat grass, but would not be able to use the glucose stored in the grass structure.

Earlier still or dark water collected in a vessel was considered or used as mirrors by ancient people. Then as days passed obsidian mirrors came into existence followed by metal coated glass mirrors this led to discovery of metal coated spherical or parabolic mirrors.  A spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface. 

There are two types of spherical mirrors: concave mirror, and convex mirror. 

These mirrors are also known as parabolic mirrors discovered in mid9th century Ibn al haytham and Ibn sahl.parabolic mirrors were described in classical antiquity written by mathematician-Diocles . In addition to these researches Ptolemy also carried out experiments with curved polished iron mirrors and discussed about convex spherical and concave spherical mirrors in his book optics.  

In spite of these researchers finding the focal length of spherical mirror was a tough task but finally Ibn al-Hay tham got a breakthrough by finding out the focal length of curved surfaces using the laws of reflection.he stated that “All the reflected rays of a mirror converge or diverge and meet at a point known as focus and the distance between focus and pole of mirror is known as  focal length of mirror.’’Also many scientists came to a conclusion that spherical mirrors can be divided into concave and convex mirrors. The invention of concave and convex mirrors led to many changes and have become a part of our life. 

Parabolic mirrors were described and studied in classical antiquity by the mathematician Diocles in his work On Burning Mirrors. Ptolemy conducted a number of experiments with curved polished iron mirrors, and discussed plane, convex spherical, and concave spherical mirrors in his Optics. Parabolic mirrors were also described by the physicist Ibn Sahl in the 10th century, and Ibn al-Haythamdiscussed concave and convex mirrors in both cylindrical and spherical geometries, carried out a number of experiments with mirrors, and solved the problem of finding the point on a convex mirror at which a ray coming from one point is reflected to another point. By the 11th century, clear glass mirrors were being produced in Moorish Spain.

Source: http://en.wikipedia.org/wiki/Mirror#History

History of spherical mirrors in human civilization:

1. The first mirrors used by people were most likely pools of water, or water. The earliest manufactured mirrors were pieces of polished stones.
2. Parabolic mirrors were described and studied in classical antiquity by the mathematician Diodes in his work on burning mirrors.
3. Ptolemy conducted a number of experiments with curved polished iron mirrors. He also discussed plane, convex, concave and spherical mirrors in his optics.
4. In China, people began making mirrors with the use of silver mercury amalgams as early as 500 AD.
5. In 16th century, Venice, a big city formed for its glass making expertise, became a centre of mirror production using this new technique.
6. The invention of the silvered - glass mirror is created to German Chemist Justus Von Liebig in 1835.

The three events that occur during the process of photosynthesis are:

• Absorption of light energy by chlorophyll.
• Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.
• Reduction of carbon dioxide to carbohydrates.

Role of stomata: Tiny openings in leaves called stomata. These help in the gaseous exchange between the plant and its atmosphere. The gas exchange that occurs when stomata are open facilitates photosynthesis. During photosynthesis, carbon dioxide is taken in from the atmosphere through the stomata and oxygen is released as a waste product. Both photosynthesis and the gas exchange that powers it are essential to the plant's survival.

History of Spherical Mirrors in Human Civilization
1. In ancient times people used to see their reflection in water and thus use it to groom themselves.

2. In stone age, polished stones replaced the pool of water. Obsidian is the required stone which occur naturally in volcanic eruption.

3. When metals were found & people got to know about its usage, then these stones were replaced by metal mirrors. Mirrors of polished copper were crafted in Mesopotamia from 4000 B.C. and in ancient Egypt from around 3000 B.C.

4. As metal & stone mirrors does not provide the desired result hence Chinese people started making mirrors using silver mercury amalgams.

5. Venice in 16th century, became the centre of mirror production using this new technique.

6. Parabolic mirrors were described and studied in classical antiquity by the mathematician Diodes in his work on burning mirrors.

7. Ptolemy conducted a number of experiments with curved polished iron mirrors. He also discussed plane, convex, concave and spherical mirrors in his optics.

8. The invention of the silvered - glass mirror is created to German Chemist Justus Von Liebig in 1835.

Correct option is D) somehow

a. False. Thermionic emission occurs in the cathode, and the released electrons are targeted on the anode target. 

b. True. This is due to its high melting point and high atomic number (Z = 74), which increases the degree of Bremsstrahlung. 

c. False. The energy of the electrons is mainly converted into heat, which is why the anode must be able to tolerate a significant temperature rise. Less than 1% is converted to X-ray photons. 

d. True. The anode may be stationary or rotating. Rotating anodes are used for better tolerance of the heat generated during the production of X-rays, as the heat is spread over a larger area. 

e. False. Rhodium (Z = 45) and molybdenum (Z = 42) are chosen due to the useful energies of characteristic radiation.

Laser ryas (characteristics)-

(i) It is used to produce mono chromatic infra-red ryas.

(ii) Laser of he-Ne produce the infra-red rays of wave-length 3.39 x 10^-6 m, 1.19 x 10^-6 m and 3.39 x 10^-6 m.

(iii) Laser of CO₂ produces the infra-red ray of wave length 10.6 x10^-6 m

Correct option is B) do I

Correct option is C) have

Correct option is A) would

Correct option is D) won’t work

Correct option is A) is late

Correct option is E) buried

Correct option is A) is not seen

B) drives / walked 

B) gets / got 

Carbohydrates present in food are broken down to form glucose. This glucose combines with oxygen in the cells of our body and provides energy; this reaction is known as respiration. Hence, respiration is considered as an exothermic reaction. 

C₆H₁₂O₆ + 6O₂ ⇾ 6CO₂ + 6H₂O + energy

Correct option is D) would be

Correct option is C) not been

Correct option is B) had happened

Correct option is C) Had you

Suman is a very foolish girl. She is lazy and inactive too. She does not take interest in whatever she does. She dislikes cooking. She dislikes sewing, she dislikes reading good books. She hates her school. She wastes her free time in school, playing or gossiping. Even at home she dislikes to stay with her mother and do things for her. She is very slow at work, and her mother never wants her help in the kitchen. She does not look after her younger brother and sister.

Dendrites of one nerve cell connect to the other or to the axons of the other nerve cells through connections called 'synapse'. It is the functional region of contact between two neurons, where information from one neuron is transmitted or relayed to another neuron. There is a gap, at synapse through which the message jumps from one neuron to the other.

As soon as Geeta put her first step into the house, she was surrounded by a group of women. Every one of them wanted to lift her sari and see her beautiful face. She patiently bore all the unfavourable remarks of the women. She had to bend down to touch the feet of over one hundred women. They all blessed her a long happy married life.

जैसे ही गीता ने अपना प्रथम पग मकान में रखा महिलाओं के एक समूह ने उसे घेर लिया। उनमें से प्रत्येक उसकी साड़ी उठाना और उसका सुन्दर मुखड़ा देखना चाहता था। उसने महिलाओं की समस्त टिप्पणियाँ धैर्य से सुनीं। उसे एक सौ से भी अधिक महिलाओं के चरण स्पर्श करने के लिये झुकना पड़ा। उन सभी ने उसे दीर्घ सुखी विवाहित जीवन का आशीर्वाद दिया।

(1) Generally fission in bacteria brings multiple number from time to time. 

(2) Hence half of the bucket is filled with them in 3 minutes. 

(3) If all the bacteria multiply at once it will take a minute to fill all the volume of bucket.

Given:

P(n) : 5n/2 < n!

n belongs to Natural number

Calculation:

P(n) : (5n)/2 < n!

Put n = 1, 2, 3 ,4, ......

For n = 1

P(1) : 5(1)/2  > 1! = 2 > 1 (false)

For n = 2

P(2) : 5(2)/2  > 2! = 5 > 2 (false)

For n = 3

P(3) : 5(3)/2  > 3! = 7.5 > 6 (false)

For n = 4

P(4) : 5(4)/2  > 4! = 10 < 24 (True)

similarly for P(5) ,P(6).... and for all n natural numbers it is true

∴ P(n) is true for n all greater than 3

The mean of first five odd numbers will be 5.

The probability P(E) of an sure event or certainly E = 1.

The number of maximum tangents from an external point is a circle is 2.

Denominator of a rational number never equal to 0.

Sum of four angles of quadrilateral will be 360° 

Value of cot 60° will be 1/√3

Probability of sure event is 1

The value of ordinate of point (–4, 5) in cartesian plan -4.

Sin(90° – A) is equal to cosA 

The correct option is: (d) 6

Decimal expansions of 17/25 is 0.68.

The correct option is: (a) 1 : 9 

Answer is (2) 9x² = 12y + 8

Let point P be (2t, t²) and Q be (h, k).

h = 2t/3, k = (-2 + t²)/3

Hence locus is 3k + 2 = (3h/2)² ⇒ 9x² = 12y + 8

What’s mode of 7, 8, 9, 7, 8, 9, 9, 3, 5, 4 9 .

The correct option is: (d) 30√3 m

cosec (90° – A) = sec A

The roots of ax² + bx + c = 0 is real and unequal if b² – 4ac > 0 

The quadrant will the point (–3, –3) lie Third quadrant 

\(\frac{d}{d\mathrm x}\frac{\mathrm x^2}{\sqrt{\mathrm x+1}}\) \(=\frac{\sqrt{\mathrm x+1}\frac{d}{d\mathrm x}\mathrm x^2-\mathrm x^2\frac{d}{d\mathrm x}\sqrt{\mathrm x+1}}{\mathrm x+1}\) (By \(\frac{U}{V}\) formula)

\(\mathrm{=\frac{2x\sqrt{x+1}-\frac{x^2}{2\sqrt{x+1}}}{x+1}}\)   \(\Big(\because\) \(\frac{d}{d\mathrm x}\mathrm x^2=2\mathrm x\) and \(\frac{d}{d\mathrm x}\sqrt{\mathrm x}=\frac{1}{2\sqrt{\mathrm x}}\Big)\)

\(\mathrm{=\frac{4x(x+1)-x^2}{x+1}}\)

\(\mathrm{\frac{3x^2+4x}{2(x+1)^{^{3}/_{2}}}}\)

Now, \(\frac{d^2}{d\mathrm x^2}\mathrm{\frac{x^2}{\sqrt{x+1}}}\) \(=\frac{d}{d\mathrm x}\mathrm{\frac{3x^2+4x}{2(x+1)^{^3/_2}}}\)

\(=\frac{1}{2}\) \(\times\) \(\mathrm{\frac{(x+1)^{\frac{3}{2}}\frac{d}{d\mathrm x}(3x^2+4x)-(3x^2+4x)\frac{d}{d\mathrm x}(x+1)^{\frac{3}{2}}}{(x+1)^3}}\)   

\(=\frac{1}{2}\) \(\times\) \(\mathrm{\frac{(6x+4)(x+1)^{\frac{3}{2}}-\frac{3}{2}\times (3x^2+4x)\times (x+1)^{\frac{1}{2}}}{(x+1)^3}}\) \((\because\) \(\frac{d}{d\mathrm x}\mathrm x^4 = n\mathrm x^{n-1})\)

\(\mathrm{=\frac{\frac{1}{2}(\mathrm x+1)^{\frac{1}{2}}((6x+4)(x+1)-\frac{3}{2}(3x^2+4x))}{(x+1)^3}}\)

\(=\frac{1}{4(\mathrm x+1)^{\frac{5}{2}}}\)\(\mathrm{(12x^2+20x+8}\) \(\mathrm{-9x^2-12x})\)

\(\mathrm{=\frac{3x^2+8x+8}{4(x+1)^{\frac{5}{2}}}}\)

Hence, second derivative of \(\frac{\mathrm x^2}{\sqrt{\mathrm x+1}}\) is \(\mathrm{\frac{3x^2+8x+8}{4(x+1)^{\frac{5}{2}}}}\).

If length of the tangent of a circle from point P is 24 cm and distance from centre of P is 25 cm then the radius of the circle is 7 cm