Explore topic-wise InterviewSolutions in Current Affairs.

(1) Tommy says these words, “I wouldn’t throw it away.”

(2) ‘It’ refers to the television screen.

(3) The speaker compares ‘it’ with a real book.

a – iv, 

b – i, 

c – ii, 

d – iii

(1) ‘They’ refers to the people of many centuries ago.

(2) Here ‘regular’ means something of a lasting nature.

(3) It is contrasted with a human teacher.

Option : b. decreasing

Atoms of the same element having the same atomic number but different mass numbers are called isotopes.

Electromagnetic radiations are emitted or absorbed or propagated in the form of small pockets of energy called photon.

The splitting of spectral lines in a magnetic field is called the Zeeman effect.

Spin quantum number is not obtained from solution of Schrodinger wave equation.

No two electrons will have same set of all q.no. If n,l,m are same i.e. same orbital ‘s’ will be differ. It shows that all electrons have a definite place in an atom or their own identity.

Correct option is  B) Aufbau

Electrons are filled in orbitals of an atom according to increasing energies which is in accordance to (n+l) values of electrons. If (n+l )values are same the electron goes to orbital having lower value of n. 

Variation of valence in a group as well as across a period in the periodic table occurs as follows:

(i) In a group: All elements in a group show the same valency. For example, all alkali metals (group 1) show a valency of +1. Alkaline earth metals, (group 2) show a valency of +2. However, the heavier elements of p-block elements (except noble gases) show two valence: one equal to the number of valence electrons or 8 - No. of valence electrons and the other two less. For example, thallium (TI) belongs to group 13. It shows valence of +3 and +1. 

Lead (Pb) belongs to group 14. It shows valance of +4 and +2. Antimony (Sb) and Bismuth (Bi) belong to group 15. They show valence of +5 and +3 being more stable. This happens due to the non-participation of the two s-electrons present in the valence shell of these elements. This non-participation of one pair of s-electrons in bonding is called inert-pair effect. 

(ii) In a period : The number of the valence electrons increases in going from left to right in a period of the periodic table. Therefore, the valency of the elements in a period first increases and then decreases.

Mass of the toy car,

m = 200 g = 0.2 kg

Speed, v = 5 m/s

Momentum, p = m x v

= 0.2 x 5 = 1 kg.m/s

The refractive index of the second medium with respect to the first medium, ₂n₁ = \(\frac{sin\,i}{sin\,r}=\frac{v_1}{v_2}\)

where i is the angle of incidence, r is the angle of refraction (as the ray of light passes obliquely from the first medium to the second medium), v₁ is the magnitude of the velocity (speed) of light in the first medium and v₂ is the magnitude of the velocity of light in the second medium.

When we consider two media (such as air and glass), the medium with lower refractive index is called the optically rarer medium (in the present case, air) and the medium with higher refractive index is called the optically denser medium (glass, in the present case).

The higher density does not necessarily mean higher refractive index. For example, the density of water is greater than that of kerosene, but the absolute refractive index of water is less than that of kerosine. Thus, when we consider water and kerosine, water is an optically rarer medium while kerosine is an optically denser medium.

If we consider kerosene and benzene, kerosine is an optically rarer medium while benzene is an optically denser medium.

The absolute refractive index of a medium is defined as the ratio of the magnitude of the velocity of light in vacuum to the magnitude of the velocity of light in the medium.

[Note: The speed of light is maximum in vacuum, about 3 × 10⁸ m/s. When light travels from one medium to another, there occurs a change in its speed and wavelength (A). But its frequency (v) remain the same.]

As the refractive index of the given material with respect to air is 1.5, the refractive index of air with respect to the material is

\(\frac{1}{1.5}=\frac{1}{3/2}=\frac{2}{3}\) = 0.6667 (approximately)

Let v₁ = speed of light in the first medium, v₂ = speed of light in the second medium, ₂n₁ = refractive index of the second medium With respect to the first medium and ₁n₂ = refractive index of the first medium with respect to the second medium.

By definition, ₂n₁ = \(\frac{v_1}{v_2}\) and ₁n₂ = \(\frac{v_2}{v_1}\)

Hence,

₁n₂ = \(\frac{1}{_2n_1}\)

(OR)

₁n₂ × ₂n₁ = 1.

The actual mass of an atom should be equal to the sum of the mass of particles present in it. Scientists realized the fact that there is no relation between the total mass of particle, ie., electrons, and protons in an atom and the actual mass of an atom.

From this, it can be inferred that nucleus may contain neutral particles having mass equal to that of protons predicted by Rutherford. In 1932 James Chad Wick confirmed the presence of neutral particles within the nucleus of an atom. These particles are called neutrons. The mass of neutron is determined slightly higher than that of protons.

The atomic number of aluminums is 13.

Hence, the electron distribution in an aluminum atom would be 2, 8, 3.

So, A is the correct option.

(d) \(\sqrt{2} B\)
Resultant magnetic field at common centre
B = \(\sqrt{\left(B_{1}^{2}+B_{2}^{2}\right)}=\sqrt{B^{2}+B^{2}}=\sqrt{2} B\)

Electric flux ∆ø through an area element ∆S is defined by ∆ø = E.∆S = E ∆S cos θ which, is proportional to the number of field lines cutting the area element. The angle θ here is the angle between E and ∆S. 

The vector area element ∆S is ∆S = ∆S ˆn 

where ∆S is the magnitude of the area element and ˆn is normal to the area element, which can be considered planar for sufficiently small ∆S. 

For an area element of a closed surface, ˆn is taken to be the direction of outward normal, by convention. 

The unit of electric flux is N C^–1 m². 

Data is termed as a collection of mere symbols. While processing data we get information and knowledge is the organized information. It can be a piece of information that helps in decision making. The ability to draw useful inferences from the available knowledge is generally referred as intelligence. Wisdom is the maturity of the mind that directs its intelligence to achieve desirable goals.

Advantages

• Cost savings : Companies can reduce costs by using cloud computing Scalability/
• Flexibility: More resources are used when the work load increases.
• Reliability : It is reliable and helps in disaster recovery Maintenance: The service provider do the system maintenance, then reducing maintenance requirements.
• Mobile accessible : Employees can do their job even when they are in move.

Disadvantages:

• Security and privacy Security measurements must be applied otherwise the data will be misused
• Lack of standards : Clouds have no standards so it is not possible to export or import programs.

The advantages of cluster computing is given below.

Price performance ratio: The performance is high and the cost is less. 

Availability: If one group of system fails the other group will do the work.

Scalability : Computers can be easily added according to the work load increases.

A SaaS provider company provides more services on demand such as they allow to access both resources and applications.

Examples are Google Docs, Adobe creative cloud, Microsoft Oce 365, Facebook.com etc.

SaaS stands for Software as a service

Correct answer is (d) NaaS

It is an emerging computing technology. Here with the use of Internet and central remote servers to maintain data and applications. Example for this is Email service, Oce Software(word processor, spread sheets, presentations, data base etc), graphic software etc. The information is placed in a central remote server just like clouds in the sky hence the name cloud computing.

Cloud service models (3 major services) 

(1) Software as a Service (SaaS): A SaaS provider company provides more services on demand such as they allow to access both resources and applications.

Examples are Google Docs, Adobe creative cloud, Microsoft Oce 365, Facebook.com etc.

(2) Platform as a Service(PaaS): A PaaS provider company provides subscribers access to the components that they, require to develop and operate applications over the Internet.

Example : LAMP platform(Linux,Apache Server,MySQL and PHP), ASP.NET, PHP and Python, Google’s App Engine, Microsoft Azure, Force.com, etc.

(3) Infrastructure as a Service(laaS): It provides basic storage devices and computing capabilities as standardized services over the network.

Example: Amazon Web Services, Joyent, AT&T, GoGrid etc.

The quantity of heat transferred through a unit length of a material in a direction normal to Unit surface area due to a unit temperature difference under steady state conditions is known as thermal conductivity of a material

Because entropy increases when heat flows form hot object to cold object. If heat were to flow form a cold to a hot object, entropy will decrease leading to violation of second law thermodynamics.

When heated, an object receives heat from the agency. Now object has more internal energy than before. Heat is the energy in transit and which flows from an object at higher temperature to an object lower temperature. Heat is not a quantity. So the statement I would prefer “an object contains more thermal energy”.

Two systems are said to be in thermal equilibrium with each other if they are at the same temperature, which will not change with time.

The triple point of  a substance is the temperature and pressure at which the three phase (gas, liquid, and solid) of that substance coexist in thermodynamics equilibrium.

Temperature is the degree of hotness or coolness of a body. Hotter the body higher is its temperature. The temperature will determine the direction of heat flow when two bodies are in thermal contact. The SI unit of temperature is kelvin (K).

The Avogadro’s number N_A is defined as the number of carbon atoms contained in exactly 12g of ¹²C

Thermal expansion is the tendency of matter to change in shape, area, and volume due to a change in temperature.

It states that the power (E) emitted per unit area by a body at absolute temperature,T is given by E = εσT⁴

Where

E = Energy being emitted per second per unit area of surface

ε = Emissivity or emissive power of that body (which is equal to 1 for black body)

σ = Stefan’s constant = 5.67 × 10^-8 Jm^-2 K^-4 s^-1.

If temperature of the surrounding is to be taken into consideration then the net rate of loss of energy as heat per unit area per second is given by 

E = εσ(T⁴ – T₀⁴ ) 

If the total area of surface is A, then the total energy radiated in t time

E = Aεσt(T⁴ – T₀⁴ )

Latent heat capacity of a substance is defined as the amount of heat energy required to change the state of a unit mass of the material.

The elements with valency +1 are always metals present in the left most
corner of the periodic table in group I. They have only one electron in their outermost shell which they could lose easily to get an outermost shell with the maximum number of allowed electrons. But a -1 valency could be shown by the group 17 nonmetals also which have 7 electrons in their outermost shell and require only one electron to complete their octet.

Hence, the correct option is C.

J.J. Thomson proposed the first model of the atom to be similar to that of a
Christmas pudding. On the basis of Thomson’s model of an atom, an atom consists of
an electrically positively charged sphere in which negative charges are embedded. The magnitude of the positive and negative charges is equal and hence, the atom as a
whole is electrically neutral.

Heat energy from hot molten rocks present inside the Earth under certain favourable conditions created by natural process is known as geothermal energy. This form of energy is the only type of energy which do not use solar energy.

Energy from the oceans can be obtained in the form of tidal energy, wave energy and ocean thermal energy. But these energy sources suffer from the following limitations:
1. There are very few locations where dams to utilise tidal energy can be built.
2. Cost of installation of power houses is extremely high and efficiency of plants is comparatively small.
3. Power plants built in oceans or at sea shores will need high continuous maintenance as chances of corrosion are extremely high.

(i) From V to Cr E⁰ value becomes less negative because I.E and enthalpy of atomisation both increase.

(ii) And then from Cr to Mn it becomes more negative due to dip in M.P. of Mn. Now From Mn to Fe its value again decreases due to increase in Enthalpy of atomisation and I.E of Fe.

(iii) From Fe to Ni the value becomes less and less negative and in the end Cu its positive, as enthalpy of atomisation and I.E both increase.