Explore topic-wise InterviewSolutions in Current Affairs.

Correct option is (2) (C)>(A)>(B)

(A) [Ni(H₂O)₂(en)₂]²⁺

(B) [Ni(H₂O)₄,(en)]²⁺

(C) [Ni(en)₃]²⁺

en is SFL (strong field ligand)

As the number of en (strong ligand) increase splitting also increases.

So, Δ₀ increases.

i.e. maximum energy will be absorbed in case of option C.

So the order is C > A > B

(2) Diamond is sp³ hybridised and graphite is sp² hybridized.

In diamond each carbon is bonded with four other carbon atoms. So hybridisation of carbon atom is sp³.

In graphite each carbon is bonded with three other carbon atoms. So hybridisation of carbon atom is sp².

Correct option is (4) ununennium

IUPAC nomenclature

119 → Ununennium → Uue

The following reaction takes place:
   Fe  +      2HCl         ----->      FeCl₂       +      H₂
Iron     Hydrochloric acid     lron chloride   Hydrogen

Thus, hydrogen and iron chloride are produced. Therefore, (a) is the correct answer.​

(i) Displacement type

(ii) Decomposition type

We have 

64 part of O₂ reacts with 168 part of Fe 
so 8 part of O₂ will react = 168x8/64 = 21 part of Fe 
so equivalent wt ,of Fe = 21

Aluminium metal forms a thin layer of aluminium oxide all over its surface under the action of moist air. This layer prevents the metal underneath from further corrosion. It is cheap, easily available, malleable and ductile. Therefore, it is used to make utensils for cooking.

Reaction (i) will not occur because Fe is less reactive than Mg. Reaction (ii) will not occur because Cu is less reactive than Mg.

(i) Large amount of heat is evolved.
(ii) Metal starts floating.

When a piece of zinc metal is placed in a solution of mercuric chloride (HgCl₂), a white layer of mercury is deposited on zinc metal to give it silvery shining look. This is because mercury is lower to zinc in reactivity series and hence, zinc can displace mercury from HgCl₂.
But when zinc is placed in a solution of magnesium sulphate, there is no change. This is because magnesium is above zinc in the reactivity series and hence, zinc cannot displace magnesium from its salt solution.

(a) No, because oxygen is added to aluminium, therefore, it is getting oxidised.
(b) No, since manganese has lost oxygen, therefore, it is getting reduced.

Note: The displacement reactions, in which highly reactive metals such as sodium, calcium, aluminium etc. are used as reducing agents because they can displace metals of lower reactivity from their compounds. 

For example, when manganese dioxide is heated with aluminium powder, the reaction that takes place is: 

3MnO₂(s) + 4Al(s) → 3Mn(l) + 2Al₂O₃(s) + heat 

These displacement reactions are highly exothermic. The amount of heat evolved is so large that the metals are produced in the molten state. 

•The reaction of iron (III) oxide (Fe₂O₃)with aluminium is used to join railway tracks or cracked machine parts. This reaction is known as thermit reaction. 

Fe₂O₃(s) + 2Al(s) → 2Fe(l) + Al₂O₃(s) + heat

This layer formed is protective oxide layer which prevents the metal from further oxidation.

(a)  Because Pt, Au, Ag are highly malleable, highly ductile, lustrous and less reactive.

(b)  Sodium and potassium are highly reactive metal so stored under oil to protect from reaction with air.

Some alkali can be cut with a knife because they are very soft and have low densities.

Iodine is lustrous.

Correct option is C) dull

The surface of some metals acquires a dull appearance when exposed to air for a long time due to the formation of a thin layer of oxide, carbonate or sulphide on their surface by the slow action of the various gases present in air

Metal: Mercury (Hg); Non-metal: Bromine (Br) 

Two metals with melting points less than 310K are Cesium (Cs) and Gallium (Ga).

Correct answer is (d) n₁ = n₃ < n₂ 

Medium A and C in air, therefore, n₁ = n₃, but glass slab is of higher refractive index.

∴ n₁ = n₃ < n₂

Answer: rate of consumption of reactants and formation of products.

Correct option is (2) 5

sinθ tanθ + tanθ = sin2θ

tanθ (sinθ + 1) - 2 sinθ cosθ = 0

\(sin \theta \left(\frac{(sin\theta + 1)}{cos\theta} - 2 cos\theta\right) = 0\)

sinθ = 0

θ = 0

or

sinθ + 1 - 2 cos²θ = 0

sinθ + 1 - 2 (1 - sin²θ) = 0

2sin²θ + sinθ - 1 = 0

sinθ = -1, \(\frac12\)

\(\theta = -\frac\pi2,\frac\pi6,\frac{5\pi}6\)

Hence, 

\(S = \{0, \frac\pi6,\frac{5\pi}6\}\)

⇒ n(5) = 3

\(t = \sum (\theta(2\theta)) = cos(0) + cos(\frac\pi3) + cos(\frac{5\pi}3)\)

\(= 1 +\frac12 + \frac12 = 2\)

t + n(5) = 2 + 3 = 5

Correct answer is 53

B = {x = 2k; 1≤ k ≤100}

Thus, x(2,4,6,8,10,...100}

B = {2,4,6,8,10,12,...200}

Thus, n(B)=100

Now, 4= {x: HCF(x,45} = 1}

Thus, multiple of 5 and 3 should not be there

Thus, A = {1,2,4,7,8,11,13,4,...}

Thus, A ∩ B will contain elements in B which are not multiple of 2 and 5, i.e., 10, 20, ... 200

Thus, total 20

And not multiple of 3 and 2 i.e., 6, 12, 18,..., 198

Thus, total 33 - 6 = 27

Thus, n(A ∩ B) = 100-47= 53

A. True This is ‘intermittent claudication’; pain metabolites accumulate in muscle during exercise in ischaemic limbs and stimulate local pain receptors. 

B. True When the major arteries are obstructed, collateral vessels open up to help maintain blood flow to the ischaemic tissues. 

C. False Though the hyperaemias have smaller peak values, their durations are longer. 

D. True Cuts and ulcers are slow to heal because the supply of nutrients is impaired. 

E. True Pulses may be absent with severe narrowing.

Kirchhoff's second law is based on law of conservation of energy.

The correct answer is (3) 4. 

Explanation:

If monkey move downward with acceleration a then its apparent weight decreases. In that condition Tension in string =m(g−a) This should not be exceed over breaking strength of the rope i.e. 360≥m(g−a)

=>360≥60(10−a)

=> a≥ 4 m/s²

(A) B will never lose contact with the ground

(D) v_B = u/cosθ

(B) The maximum acceleration of man so that the rope just breaks is (1 - β)g.

(A) 300kg force 

(C) The magnitude of acceleration is 25m/s².

(B) √(2h/gsinθcosθ)

Work done W = KE₂ – KE₁ 

KE₁ = 1/2m₁v₁² =4000 J 

KE₂ = 1/2mv₂² = 250 J 

Arriving at final answer 

W = KE₂ – KE₁ 

= 4000 – 250 = 3750 J

Correct answer is (a) 110m

Distance travelled in n^th second, u = 0 

S_n = u + \(\frac{1}{2}\)a(2n – 1) 

S₆ = 0 + ×\(\frac{1}{2}\) 20 × (2 × 6 – 1); S₆ = 110 m

Explanation:

• Ministry of Environment and Forests (MoEF) is the nodal agency in the administrative structure of the Central Government for planning, promotion, co-ordination and overseeing the implementation of India’s environmental and forestry policies and programmes. 

• The ministry is responsible for planning, promoting, coordinating, and overseeing the implementation of environmental and forestry programmes in the country.
• The main activities undertaken by the ministry include conservation and survey of the flora of India and fauna of India, forests and other wilderness areas; prevention and control of pollution; afforestation, and land degradation mitigation.
• It is responsible for the administration of the 1947 national parks of India.
• The Ministry of Environment, Forest and Climate Change is the cadre controlling authority of the Indian Forest Service (IFS), one of the three All India Services. 

The correct option is (1) 2 protons and 2 neutrons only.

Explanation:

α-particle is nucleus of Helium which has two protons and two neutrons.

The correct answer is 1992.

• The Earth Summit 1992  is also known as The United Nations Conference on Environment and Development (UNCED) held at Rio de Janeiro (Brazil).

The Outcome of Earth Summit 1992 - 

Few such important Conferences are-

Hence, Brazil hosted the First World Earth Summit (1992) convention on the environment.