#jeemain
- Which of the following polymer is used in the manufacture of wool laminates ? The correct answer is option (1) Urea formaldehyde resin Explanation:: 1
- The type pollution that gets increased during the day time and in the presence of O3 is : (2) Oxidising smog In presence of ozone(O3), oxidising smog gets increased during the day time because automobiles and factories produce mai... 1
- Which of the following reaction DOES NOT involve Hoffmann bromamide degradation ? The correct answer is option 3) This reaction does not involve haffmann bromanide degradation Rest all options involve haffmann bromamide de... 1
- The process that involves the removal of sulphur from the ores is : jee main march 2021 1) roasting Removal of sulphur from the ore is done by Roasting. 1
- A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The correct answer is option 2 ) Bi 2
- Which polymer is used in the manufacture of paints and lacquers? Correct answer is option B) Glyptal Explaination:: Gylptal is a polymer obtained by condensation polymerization of glycerol and phthalic anh... 1
- A 25 m long, antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The correct answer is option 3) 100 m Explanation: height of antenna= λover 4 25= λover 4 λ=100 1
- The maximum and minimum distances of comet from the Sun are 1.6 × 1012 m and 8.0 × 1010 m respectively The correct answer is option A) 3.0×10³ m/s Explanation:: L=mv₁r₁=mv₂r₂ V₂= v₁r₁over r₂ =v₁ 8×10¹⁰over 160×10¹⁰ =6×10⁴over 20 =3000 m/s 1
- 22 Ne nucleus, after absorbing energy, decays into two α-particles and an unknown nucleus. The unknown nucleus is The correct answer is option B) carbon Explanation:: ²²Ne decays α particle = He²⁺ Mass No = 4 p=2,n=2 So, New mass no. =22−8=14 Atomic No.... 1
- A aeroplane is flying horizontally with speed of 432 km/hr at height h meter from ground. Its angle of elevation The correct answer is option A)1200 sqrt3 Explanation:: 1
- Mass of Li3+ is 8.33 times mass of proton Li3+ and proton are accelerated through same potential difference. Then ratio of debroglie's The correct answer is 2 Explanation:: 1
- If A=[ 1 2 2 2 1 2 2 2 1] and A^-1 exists and A≠0 , then (A^2-4A)A^-1= The correct answer is option a) beginbmatrix -3& 2 & 2\\ 2 & -3& 2\\ 2&2&-3 endbmatrix Video explaination:: https://youtu.be/7B6Et9Lb3gw 1
- A stationary body explodes into two fragments each of rest mass 1kg that move apart at speeds of 0.6c relative to the original body Correct answer is option is B) 2.5 kg 1
- Given that x = -9 is a root of ||The other two roots are ______ and ________ . the correct answer is available here watch this video by neha mam 2
- If the lines ax + y + 1 = 0, x + by + 1 = 0 and x + y + c = 0 (a, b, c being distinct and different from 1 ) are concurrent, then value of The correct answer is option c) 1 if the given lines are concurrent , then beginarray|ccc|cc| a& 1 & 1 \\ 1 & b & 1\\ 1 &1 & c\\ endarray=0... 1
- As per IUPAC nomenclature, the name of the complex [Co (H2O)4(NH3 )2]C13 is correct option is d) diamminetctraaquacobalt (III) chloride First of all, the compound has complex positive part [Co(H₂O)₄(NH₃)₂]₃₊ therefor... 1
- The oxidation state of Fe in the brown ring complex [Fe(H2O)5NO]SO4 is:(a) + 1 (b) + 2 (c) + 3 (d) + 4 Corret option is a) +1 Explaination :: [Fe(H₂O)₅NO]SO_(4 → ([Fe(H₂O)₅NO] )⁺²+(SO₄)⁻²) (fe^+)⁺¹ =+2 charge on fe= +1 1
- The number of enantiomer in a glucose molecule is (a) 16 (b) 12 (c) 4 (d) 9 Correct option is A) 16 Explaination: Glucose molecule the number of chiral carbon is = 4 Formula for enantiomer, = 2ⁿ total number of enant... 1
- Area (in sq. units) of the region outside |x|/2 + |y|/3 = 1 and inside the ellipse x^2/4 + y^2/9 = 1 is The correct answer is option c) 6( π-2) Explaination:: Area of Ellipse =πab=6π Area |x|over2+|y|over3=1 is =1over2(d₁d₂)=1over2(4)(6)=12 so... 1
- Two capacitors C1 and C2 are charged to 120 V and 200 V, respectively. correct answer is option (c) 3C₁ = 5C_(2 ) Explaination:: For potential to be made zero, after connection 120C₁ = 200C₂ 6C₁ = 10C₂ 3C₁ = 5C₂ 1
- Select the correct stability order of the conformation /Rotamers/ Rotational isomers of Ethane Molecule The correct answer is c) Anti-staggered > Skew or Gouche > Partially Eclipsed > Fully Eclipsed EXplaination :: The isomers which can be prod... 1
- According to molecular orbital theory, the species among the following that does not exist is: The correct answer is d) Be₂ According to M.O.T. If bond order of chemical species is zero then that chemical species does not exist Chemica... 1
- In Freundlich adsorption isotherm at moderate pressure, the extent of adsorption (x/m) is directly proportional to Px. The value of x is: The correct answer is d) 1/n Solution: (xover m)=KP^(1over n) x=1over n 1
- For octahedral Mn(II) and tetrahedral Ni(II) complexes, consider the following statements: The correct answer is b) (I), (II) and (III) only {answer by NTA} Explaination :: 1