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Find the value of 9 in the number 1,904,712

The place value of 9 in the number 1,904,712 is nine hundred thousand 1 million Hundred Thousand Ten Thousand Thousands... View Article

Find the number of digits in the square root of each of the following (without any calculation) a) 144 b) 2500

a) Number of digits in 144 = 3 Number of digits in the square root of 144 = (n+1)/2 { when n is odd} = (3 + 1)/2 = 2 b) Number of digits in... View Article

If the wage of 45 women amounts to ₹ 15525 in 48 days, how many men must work for 16 days to receive ₹ 5750, the daily wage of a man being double that of a woman?

Wages of 45 women for 48 days = ₹ 15525 Daily wage of 1 woman = ₹ 15525/(45 × 48) = ₹ 115/16 Given, daily wages of a man = 2 ×... View Article

A lot contains 10 items out of which 3 are defective. Three items are chosen from the lot one after another at random without replacement. Find the probability that all three are defective.

For the first draw: Number of defective balls = 3 Total number of balls in the bag = 10 Probability of drawing defective ball = 3/10 For the... View Article

The solutions of the equation |(x,2,-1),(2,5,x),(-1,2,x)|=0 are

Given equation ⇒ ⇒ ⇒ ⇒ Therefore x = 3, -1... View Article

Under root 201/529

The square root of 201/529... View Article

Factors of 3750

Factors of 3750 are 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75, 125, 150, 250, 375, 625, 750, 1250, 1875 Prime factorisation of 3750 is 2 × 3... View Article

If sec a = 2516, find cos a

We know that sec x = 1/cos x Therefore, cos a = 1/sec a = 1/2516 = 3.975 × 10-4 (approx)... View Article

oxidation of benzene by v2 of fire in the presence of air produces

The oxidation of benzene by V2O5 in the presence of air produces maleic anhydride. The oxidation is carried out at 500oC. ... View Article

The rate constant k1 of a reaction is found to be double that of rate constant k2 of another reaction. The relationship between corresponding activation energies of the two reactions at same temperature (E1 and E2) can be represented as:

We already know that the Arrhenius equation has the following expression:k=Ae−EaRT When the activation energy of a reaction increases,... View Article

camphor chiral centers

Enantiomers are compounds that are mirror reflections of each other and are non-superimposable. The light is rotated in opposing directions by... View Article

calculate the oxidation number of sulphur in h2s4o6. count for the fallacy if any

Any component that is free has an oxidation number of zero. When compared to the particle, the oxidation number for monatomic particles is... View Article

Assertion (A): Noble gases have very low boiling points. Reason (R): All noble gases have general electronic configuration of ns^(2)np^(6) (except He).

Noble gases have very low boiling points due to weak dispersion forces. Their general electronic configuration is ns2np6 (except He). In... View Article

A proton, an electron, and a helium nucleus, have the same energy. They are in circular orbits in a plane due to magnetic field perpendicular to the plane, let rp, re, rHe be their respective radii, then a) re>rp>rHe b) rerp=rHe d) re

r = mv/qBr ∝ √m/q [ K.E is ome for all particles]MHe2+ = 4mp,qH4e + 2qpmp>me rp = k(√mp/qp)k = √(2(K.E.)/B)re =... View Article

The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of slag. A. 2C(s)+O2→2CO2(g) B. CaCO3(s)→CaO(s)+CO2(g) C. CaO(s)+SiO2(s)→CaSiO3(s)

Around 1270 K (middle portion), decomposition of limestone gives lime (CaO) and CO2. Lime is a flux and combines with silicate impurity to form... View Article

The mixed anhydride of nitrogen is: (A) N2O2(NO) (B) N2O4(2NO2) (C) N2O5 (D) N2O2

When ammonium nitrate is heated, nitrous oxide is produced.NH4NO3 → ΔN2O+2H2O When sodium nitrate reacts with ferrous sulphate in an... View Article

For the spinel structure MgAl2O4, the correct statement is / are This question has multiple correct options A) 50% of the octahedral voids are occupied by ions B) Al3+ ions are equally distributed in tetrahedral voids and octahedral voids. C) Oxide ions occupy ccp lattice D) 12.5% of the tetrahedral voids are occupied by ions.

For spinel structure, O2− ions from FCC arrangement.Therefore, Number of O2− ions = 4.Number of TV = 8, Number of OV = 4Number of... View Article