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Medical
1 week, 6 days ago

Two similar thin equiconvex lenses , of focal length f each , are kept  coaxially in contact  with each other such that the focal length of the combination is F_1 . When the space between the two lenses is filled  with glycerin  then the equivalent  focal length is F_2 . The ratio F_1 : F_2 

  • Option 1)

    2 : 1 

  • Option 2)

    1 : 2 

  • Option 3)

    2 : 3 

  • Option 4)

    3 : 4 

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P Plabita
Answered 1 week, 5 days ago
Option 1)2 : 1 Option 2)1 : 2 Option 3)2 : 3 Option 4)3 : 4 
Medical
1 week, 6 days ago

The non-essential amino acid among the following is:

  • Option 1)

    valine

  • Option 2)

    leucine

  • Option 3)

    alanine

  • Option 4)

    lysine

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S solutionqc
Answered 1 week, 5 days ago
Non essential amino acids are those which produce in the human body itself. Essential amino acids are those which do not produce in the human body & we have to take them from outside sources. Alanine is the non-essential amino acid. Option 3 is correct.Option 1)valineOption 2)leucineOption 3)alanineOption 4)lysine
Medical
1 week, 6 days ago

For an ideal solution, the correct option is:

  • Option 1)

    \Delta_{mix}S = 0 at constant T and P

  • Option 2)

    \Delta_{mix}V \neq 0 at constant T and P

  • Option 3)

     \Delta_{mix}H = 0 at constant T and P

  • Option 4)

    \Delta_{mix}G = 0 at constant T and P

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S solutionqc
Answered 1 week, 5 days ago
For an ideal solution, the Gibbs free energy is always negative, thus their mixing is always spontaneous. The volume change of the mixing of ideal solutions is zero. An ideal solution is one in which the enthalpy of the solution is zero  at constant T and P Option 3 is correct.Option 1) at constant T and POption 2) at constant T and POption 3)  at constant T and POption 4) at constant T and P
Medical
1 week, 6 days ago

For the cell reaction

2Fe^{3+}(aq)+ 2I^{-}(aq) \rightarrow 2Fe^{2+}(aq) + I_2(aq)

E^0_{cell} = 0.24V at 298K. The standard Gibbs energy (\Delta_r G^0) of the cell reaction is:

[Given that Faraday constant F = 96500 C mol-1]

  • Option 1)

    -46.32 kJ mol-1

  • Option 2)

    -23.16 kJ mol-1

  • Option 3)

    46.32 kJ mol-1

  • Option 4)

    23.16 kJ mol-1

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S solutionqc
Answered 1 week, 5 days ago
We know that       Option 1 is correctOption 1)-46.32 kJ mol-1Option 2)-23.16 kJ mol-1Option 3)46.32 kJ mol-1Option 4)23.16 kJ mol-1
Medical
1 week, 6 days ago

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor M is:

  • Option 1)

    Be

  • Option 2)

    Mg

  • Option 3)

    Ca

  • Option 4)

    Sr

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P Plabita
Answered 1 week, 5 days ago
Option 2 Mg is the alkaline earth metal as the co-factor. (FACT)Option 1)BeOption 2)MgOption 3)CaOption 4)Sr
Medical
1 week, 6 days ago

A compound is formed by cation C and anion A. The Anions form hexagonal close packed lattice and the cations occupy 75% of the octahedral void. The formula of the compound is

  • Option 1)

    C_2A_3

  • Option 2)

    C_3A_2

  • Option 3)

    C_3A_4

  • Option 4)

    C_4A_3

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S solutionqc
Answered 1 week, 5 days ago
Option 3 Anions: No of ions per unit in HCP = 6 Cations: No of octahedral voids in HCP = 6                         So, 75% of 6 = 4.5     Option 1)Option 2)Option 3)Option 4)
Medical
1 week, 6 days ago

A gas at 350K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The  correct  option about the gas and its compressibility factor (Z) is:

  • Option 1)

    Z>1 and attractive forces are dominant

  • Option 2)

    Z>1 and repulsive forces are dominant

  • Option 3)

    Z<1 and attractive forces are dominant

  • Option 4)

    Z<1 and repulsive forces are dominant

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P Plabita
Answered 1 week, 5 days ago
Option 3          Molar volume of gas is 20% smaller than that of the ideal gas. Hence Z < 1 and attractive forces are dominant. When Z < 1: Gas shows negative deviation and is more compressible than expected from ideal behaviour.  Z < 1 corresponds to attractive forces between molecules.Option 1)Z>1 and attractive forces are dominantOption 2)Z>1 and repulsive forces are dominantOption 3)Z<1...
Medical
1 week, 6 days ago

The biodegradable polymer is:

  • Option 1)

    nylon-6,6

  • Option 2)

    nylon 2 - nylon 6

  • Option 3)

    nylon-6

  • Option 4)

    Buna-S

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P prateek
Answered 1 week, 5 days ago
Option 2  Biodegradable polymer is Nylon-2-Nylon-6 monomers: Glycine, aminocaproic acid Option 1)nylon-6,6Option 2)nylon 2 - nylon 6Option 3)nylon-6Option 4)Buna-S
Medical
1 week, 6 days ago

For the chemical reaction

N_2(g) + 3H_2(g)\leftrightharpoons 2NH_3(g)

the correct option is:

 

  • Option 1)

    -\frac{1}{3}\frac{d[H_2]}{dt} = -\frac{1}{2}\frac{d[NH_3]}{dt}

  • Option 2)

    -\frac{d[N_2]}{dt} = {2}\frac{d[NH_3]}{dt}

  • Option 3)

    -\frac{d[N_2]}{dt} = \frac{1}{2}\frac{d[NH_3]}{dt}

  • Option 4)

    {3}\frac{d[H_2]}{dt} ={2}\frac{d[NH_3]}{dt}

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S solutionqc
Answered 1 week, 5 days ago
For a chemical reaction: The rate is always given as:  for the reaction: , Thus,  Option 3 is correct.Option 1)Option 2)Option 3)Option 4)
Medical
1 week, 6 days ago

The total energy of an electron in an atom in an orbit is -3.4 eV . Its kinetic and potential energies are respectively  

 

  • Option 1)

    -3.4 e V, -3.4 eV 

  • Option 2)

    -3.4 e V , - 6.8 e V 

  • Option 3)

    3.4 e V , - 6.8 e V 

  • Option 4)

    3.4 e V , 3.4 e V 

 

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V Vakul Arora
Answered 1 week, 5 days ago
Option 1) -3.4 e V, -3.4 eV  Option 2) -3.4 e V , - 6.8 e V  Option 3) 3.4 e V , - 6.8 e V  Option 4) 3.4 e V , 3.4 e V 
Medical
1 week, 6 days ago

Under isothermal condition, a gas at 300K expands from 0.1L to 0.25L against a constant external pressure of 2 bar. The work done by the gas is:

[Given that 1L bar = 100 J]

  • Option 1)

    -30 J

  • Option 2)

    5 kJ

  • Option 3)

    25 J

  • Option 4)

    30 J

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S solutionqc
Answered 1 week, 5 days ago
We know that the work done is given as: Now, Option 1 is correct.Option 1)-30 JOption 2)5 kJOption 3)25 JOption 4)30 J
Medical
1 week, 6 days ago

A soap bubble , having radius of 1 mm is blown from, a detergent solution having a surface tension , of 2.5 \times 10 ^{-2 } N/m. The pressure inside the bubble equals at a point Z_0 below  the free surface of water in a container of water = 10 ^ 3 Kg / m ^ 3 , the value of Z_0 is 

  • Option 1)

    100 cm 

  • Option 2)

    10 cm 

  • Option 3)

    1 cm 

  • Option 4)

    0.5 cm 

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A aadil.khan
Answered 1 week, 5 days ago
Option 1)100 cm Option 2)10 cm Option 3)1 cm Option 4)0.5 cm 
Medical
1 week, 6 days ago

Which of the following reactions are disproportionation reaction?

(a) 2Cu^+ \rightarrow Cu^{2+} + Cu^0

(b) 3MnO^{2-}_{4} + 4H^+ \rightarrow 2MnO_2 + 2H_2O

(c) 2KMnO_4^{-}\overset{\Delta}\longrightarrow K_2MnO_4 + MnO_2 + O_2

(d) 2MnO_4^- + 3Mn^{2+} + 2H_2O \rightarrow 5MnO_2 + 4H^{\bigoplus}

Select the correct option from the following:

 

  • Option 1)

    (a) and (b) only

  • Option 2)

    (a), (b) and (c)

  • Option 3)

    (a), (c) and (d)

  • Option 4)

    (a) and (d) only

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A aadil.khan
Answered 1 week, 5 days ago
Option 1 Disproportionation is a type of redox reaction in which a species is simultaneously reduced and oxidised forming two different products.  (a)  (b) Option 1)(a) and (b) onlyOption 2)(a), (b) and (c)Option 3)(a), (c) and (d)Option 4)(a) and (d) only
Medical
1 week, 6 days ago

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:

  • Option 1)

    t = 0.693/k

  • Option 2)

    t = 6.909/k

  • Option 3)

    t = 4.606/k

  • Option 4)

    t = 2.303/k

 

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S solutionqc
Answered 1 week, 5 days ago
Option 3 For first order reaction,               Option 1) t = 0.693/k Option 2) t = 6.909/k Option 3) t = 4.606/k Option 4) t = 2.303/k
Medical
1 week, 6 days ago

The structure of intermediate A, in the following reaction, is:

  • Option 1)

  • Option 2)

  • Option 3)

  • Option 4)

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A aadil.khan
Answered 1 week, 5 days ago
Option 2   Cumene is oxidized in air, which removes the tertiary benzylic hydrogen from cumene and hence forms cumene radical. The cumene radical then bonds with an oxygen molecule to give cumene peroxide radical, which in turn forms cumene hydroperoxide by abstracting benzylic hydrogen from the cumene molecule.  Option 1)Option 2)Option 3)Option 4)
Medical
1 week, 6 days ago

Among the following, the reaction that proceeds through an electrophilic substitution is:

  • Option 1)

  • Option 2)

  • Option 3)

  • Option 4)

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S solutionqc
Answered 1 week, 5 days ago
The electrophilic substitution reaction is: Option 2 is correct  Option 1)Option 2)Option 3)Option 4)
Medical
1 week, 6 days ago

The most suitable reagent for the following conversion is:

H_{3}C -C\equiv C-CH_{3}\xrightarrow[quinoline]{H_{2},Pd/C,}

  • Option 1)

    Na/liquid NH3

  • Option 2)

    H2, Pd/C, Quinoline

  • Option 3)

    Zn/ HCl

  • Option 4)

    Hg2+/H+, H2O

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P Plabita
Answered 1 week, 5 days ago
Option 1)Na/liquid NH3Option 2)H2, Pd/C, QuinolineOption 3)Zn/ HClOption 4)Hg2+/H+, H2O
Medical
1 week, 6 days ago

The manganate and permanganate ions are tetrahedral, due to:

 

  • Option 1)

    The \pi-bond involves overlap of p-orbitals of oxygen with d-orbitals of manganese.

  • Option 2)

    There is no \pi-bonding.

  • Option 3)

    The \pi-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese

  • Option 4)

    The \pi-bonding involves overlap of d-orbitals of oxygen with d-orbitals of manganese.

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P prateek
Answered 1 week, 5 days ago
Option 1 Manganate ion:-   [Green, paramagnetic] Permanganate ion:-  [purple, diamagnetic]   These ions are tetrahedral in shape. The -bonding takes place by overlap of p-orbitals of oxygen with d-orbitals of manganese.Option 1)The -bond involves overlap of p-orbitals of oxygen with d-orbitals of manganese.Option 2)There is no -bonding.Option 3)The -bonding involves the overlap of p-orbitals of...
Medical
1 week, 6 days ago

The unit of thermal conductivity is : 

  • Option 1)

    JmK^{-1}

  • Option 2)

    Jm^{-1}K^{-1}

  • Option 3)

    WmK^{-1}

  • Option 4)

    Wm^{-1}K^{-1}

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V Vakul Arora
Answered 1 week, 5 days ago
Option 1)Option 2)Option 3)Option 4)
Medical
1 week, 6 days ago

Which of the following diatomic molecular species has only \pi-bonds according to Molecular Orbital Theory?

  • Option 1)

    O2

  • Option 2)

    N2

  • Option 3)

    C2

  • Option 4)

    Be2

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S solutionqc
Answered 1 week, 5 days ago
Molecular orbital diagram for C2:  both are  bondsOption 1)O2Option 2)N2Option 3)C2Option 4)Be2
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