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nikhil04
@nikhil04
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Joined: Aug 19, 2020
Last seen: Jan 13, 2022
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Answer to: An alkaline earth metal 'M' readily forms water soluble sulphate and water insoluble hydroxide.

(4) Be Explanation: BeSO4 - Soluble in water Be(OH)2 - Insoluble in water Structure of BeO is Hexagonal Wurtzite.

4 years ago
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Answer to: The incorrect statement(s) among (a) - (c) is (are) : (a) W(VI) is more stable than Cr(VI).

(3) (b) only Explanation: (a) In transition metals on moving down the group higher oxidation states are more stable due to smaller size of atoms, ...

4 years ago
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Answer to: On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are :

(4) Li2O, Na2O2 and KO2 Explanation: On heating in excess air Li form oxide sodium form peroxide while K, Rb, Cs form superoxide.

4 years ago
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Answer to: The region in the electromagnetic spectrum where the Balmer series lines appear is :

(4) Visible Explanation: In hydrogen spectrum maximum lines of Balmer series lies in visible region.

4 years ago
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Answer to: For one mole of an ideal gas, which of these statements must be true?

(3) (a), (c) and (d) Explanation: (a) For ideal gas U and H are function of Temperature U = f/2 nRT (c) CP –CV = R (d) ΔU = CVdT for all proce...

4 years ago
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Answer to: The ionic radii of O^2–, F^–, Na^+ and Mg^2+ are in the order :

(1) O2– > F– > Na+ > Mg2+ Explanation: O2– F– Na+ Mg2+ Z 8 9 11 12 No. of e– 10 10 10 10 ...

4 years ago
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Answer to: The elements with atomic numbers 101 and 104 belong to, respectively:

(1) Actinoids and Group 4 Explanation: 89Ac → 103Lr Belongs to actinoids series and they all belongs to 3rd group. So atomic no. 101 element is ...

4 years ago
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Answer to: Orange light of wavelength 6000 × 10^–10 m illuminates a single slit of width 0.6 × 10^–4 m.

Light of wavelength 6000 × 10–10 m passes through a single slit of width 0.6 × 10–4 m. Find height of highest order of minima on both side central max...

4 years ago
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Answer to: The change in the magnitude of the volume of an ideal gas when a small additional pressure ΔP is applied at a constant temperature

PV = nRT PΔV + VΔP = 0 ΔV = - ΔP/P V ...(i) In second case PΔV = -nRΔT ΔV = nRΔT/P ....(ii) equating (i) and (ii) nRΔT/P = - ΔP/P V ...

4 years ago
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Answer to: The distance between an object and a screen is 100 cm. A lens can produce real image of the object on the screen for two different positions

f = D2 - d2/4D = 1002 - 402/4(100) = (100 + 40)(100-40)/4(100) = 21 cm P = 1/f = 100/21 = N/100 N = 476.19

4 years ago
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Answer to: Find the Binding energy per nucleon for 12050Sn. Mass of proton mp = 1.00783 U, mass of neutron mn = 1.00867 U

(2) 8.5 MeV Explanation: Binding energy = (ΔM)C2 = (ΔM) 931 put the value of ΔM BE = 8.5 MeV

4 years ago
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Answer to: A cube of metal is subjected to a hydrostatic pressure 4GPa. The percentage change in the length of the side of the cube is close to :

(1) 1.67 Explanation: ΔP = (B)Δv/v = B x 3 ΔL/L Putting the value of ΔP and B we get ΔL/L x 100 = 1.67

4 years ago
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4 years ago
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Answer to: A circular coil has moment of inertia 0.8 kg m^2 around any diameter and is carrying current to produce a magnetic moment of 20 am^2.

(2) 10 rad s–1 Explanation: From energy conservation 1/2Iω2 = Uin - Ur = – MB cos60º – (–MB) MB/2 = 1/2Iω2 20 x 4/2 = 1/2(0.8)ω2 100 =...

4 years ago
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Answer to: Consider two uniform discs of the same thickness and different radii R1 = R and R2 = αR made of the same material.

(1) 2 Explanation: Moment of inertia of disc is given by I = MR2/2 = [ρ(πR2)t]R2 I ∝ R4 I1 / I2 = (R2/R4)4 16/1 = α4 α = 2

4 years ago
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Answer to: The driver of bus approaching a big wall notices that the frequency of his bus's horn changes from 420 Hz to 490 Hz

(4) 91 kmh–1 Explanation: Frequency appeared at wall fw = 330/(330 - v).f ....(1) f' = 330 + v/330.fw = (330 + v)/(330 - v).f 490 = 330 + /...

4 years ago
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4 years ago
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Answer to: A closed vessel contains 0.1 mole of a monoatomic ideal gas at 200 K.

(0.1) (200) + (0.05) (400) = (0.15)T T = 20 + 20/0.15 = 800/3 = 266.67

4 years ago
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Answer to: A air bubble of radius 1 cm in water has an upward acceleration of 9.8 cms^–2.

(1) 4.15 gm Explanation: Fb - mg = ma Fb = m(g + a) = 4/3πr3ρg = m(g + a) m = 4/3π(1)g = m(980 + 9.8) m = 4.15

4 years ago
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