Doubtly
@Doubtly · Joined Feb 2021
- Answers
- 3,792
- Questions
- 4,033
- Upvotes received
- 424
- 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
- Which of the following statement(s) is (are) correct ? (A) The rest mass of a stable nucleus is less than the The correct answer is option A ) The rest mass of a stable nucleus is less than the sum of the rest masses of its separated nucleons. 2
- The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true? The correct answer is option A) Its kinetic energy increases and its potential and total energies decrease. 1
- Photoelectrons are emitted when 400 nm radiation is incident on a surface of work function 1.9eV. =-54.4 eV, -13.6 eV, -6.04 eV, -3.4 eV, -2.176 ev, -1.51 eV Difference of energies lying between 2 and 4 eV is -3.4+6.04=2.64 eV -2.176+6.04... 2
- The ratio of series limit wavelength of Balmer series to wavelength of first line of paschen series is ………. 7/36 is answer https://lh3.googleusercontent.com/-djiaQ2JfDPE/YayM6Plq9AI/AAAAAAAAC2o/a8czELAm8tUaT_CogztAF--yBfNQCikxwCNcBGAsYHQ/image.png 1
- A parallel beam of uniform, monochromatic light of wavelength 2640 A has an intensity of 200W/m2 . The number of photons in 1mm3 of this radiation are …. Solution is 884 photons/mm³ 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
- Find the initial momentum of electron if the momentum of electron is changed by pm and the De Broglie wavelength associated with it changes by 0.50 % Initial momentum is 200p_m Explaination: dλoverλ× 100 =0.5 dλoverλ× 100 =0.5over100=1over200 and triangle p=p_m p=hoverλ, differentiating dp... 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
- The top of a ladder 6 metre long is resting against a vertical wall on a level pavement, Answer: The top slides down at 1/√(5) ≈ 0.447 m/s. Let the foot of the ladder be x m from the wall and the top be y m above the ground. The... 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
- Find out the number of enantiomer, meso isomer and total number of optical isomers for the following compound Correct option is C) 4,0,4 explaination : Number of enantiomer = 2n (n is the number of chiral carbon ) Number of meso isomer = 0 Total numb... 1
- computer science college website project maharashtra board Index.html <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta na... 2