Recent questions tagged class12

Consider the following reaction number of stereo isomers formed in this reaction is

asked Feb 21, 2014 by sreemathi.v

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The appropriate reagents for the following transformation:

asked Feb 21, 2014 by sreemathi.v

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Find the ratio of De-Broglie wavelength of molecules of hydrogen and helium which are at temperatures $\;27^{0} C \;and\; 127^{0} C \;$ respectively

asked Feb 21, 2014 by yamini.v

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An electron is accelerated by a potential difference of 50 Volt ., then the de-Broglie wavelength associated with it .

asked Feb 21, 2014 by yamini.v

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In the below reaction what is A?

asked Feb 21, 2014 by sreemathi.v

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A particle is moving with velocity $ \hat i+ 3\hat j$ and it produces an electric field $ 2\hat k$ at a point. It will produce magnetic field at that point equal to

asked Feb 21, 2014 by thanvigandhi_1

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Sun gives light at rate of $\;1400 Wm^{-2}\;$ of area perpendicular to direction of light . Assume $\;\lambda\;$ (sun light )= $\;6000 A^{0}\;.$ Then no.of Photons emitted from sun/sec assuming average radius of earth's orbit is $\;1.49\times10^{11} m\;$ is

asked Feb 21, 2014 by yamini.v

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The amount of energy gained in half a revolution by an electron of mass m, velocity v and charge e in a uniform magnetic field is

asked Feb 21, 2014 by thanvigandhi_1

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Which of the following compounds form two isomeric oximes on reacting with $NH_2OH$

asked Feb 21, 2014 by sreemathi.v

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Sun gives light at rate of $\;1400 Wm^{-2}\;$ of area perpendicular to direction of light . Assume $\;\lambda\;$ (sun light )= $\;6000 A^{0}\;.$ Then no.of Photons/sec arriving at $\;1m^2\;$ area at that part of earth is

asked Feb 21, 2014 by yamini.v

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What is the major organic product obtained from the following reaction?

asked Feb 21, 2014 by sreemathi.v

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The intensity of direct sunlight before it passes through the earth's atmosphere is $\;1.4 KW/m^2\;.$ If it is completely obsorved than the corresponding radiation pressure :

asked Feb 21, 2014 by yamini.v

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In the below reaction the product of A is

asked Feb 21, 2014 by sreemathi.v

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What is the product of the following series of reactions?

asked Feb 21, 2014 by sreemathi.v

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When a charged particle passes through a region of uniform magnetic field

asked Feb 21, 2014 by thanvigandhi_1

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Two observers moving with different velocities see that a point charge produces same magnetic field at a point $A$. Their relative velocity must be parallel to , $ \overrightarrow r$ where $ \overrightarrow r$ is the position vector of point $A$ w.r.t. the point charge. This statement is

asked Feb 21, 2014 by thanvigandhi_1

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A paramagnetic substance is kept in a weak magnetic field and its absolute temperature $T$ is increased. As a result, its magnetisation

asked Feb 21, 2014 by thanvigandhi_1

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A particle is projected perpendicular to a uniform magnetic field. The area bounded by the trajectory of the particle is directly proportional to

asked Feb 21, 2014 by thanvigandhi_1

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A current carrying loop in a magnetic field behaves like a

asked Feb 21, 2014 by thanvigandhi_1

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A wire of length $\ell$ carrying a current $i$ is bent to form a circle. Its magnetic moment is

asked Feb 21, 2014 by thanvigandhi_1

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The direction of magnetic lines of force produced by passing a direct current through a conductor is determined by

asked Feb 21, 2014 by thanvigandhi_1

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A proton moves in a circular path perpendicular to a magnetic field. If the intensity of the field is doubled and the radius of the circular path is constant, then the kinetic energy of the particle has

asked Feb 21, 2014 by thanvigandhi_1

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Which of the following statement is false for the equation $ \overrightarrow F = q( \overrightarrow V \times \overrightarrow B)$

asked Feb 21, 2014 by thanvigandhi_1

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Two protons whose velocities are in the ratio $4 : 1$, move perpendicular to a uniform magnetic field, the ratio of the radii of their paths will be

asked Feb 21, 2014 by thanvigandhi_1

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The intensity of the magnetic field due to a current carrying coil is maximum at

asked Feb 21, 2014 by thanvigandhi_1

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The intensity of the magnetic field at any point due to a current carrying element depends on

asked Feb 21, 2014 by thanvigandhi_1

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A constant current flows along the length of a thin-walled, infinitely long, cylindrical pipe. Then magnetic field

asked Feb 21, 2014 by thanvigandhi_1

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A particle of charge $q$ and mass $m$ moves in a circular orbit with radius $r$ and angular speed $ \omega$. The ratio of the magnitude of magnetic moment to its angular momentum depends on

asked Feb 21, 2014 by thanvigandhi_1

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An ionized gas contains both $+ve$ and $-ve$ ions. If an electric field is applied in the $+x$ direction and a magnetic field is applied in the $+z$ direction,

asked Feb 21, 2014 by thanvigandhi_1

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Which reagent would you use to accomplish this transformation?

asked Feb 20, 2014 by sreemathi.v

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What is the most likely result of the reaction conditions shown?

asked Feb 20, 2014 by sreemathi.v

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Complete the following reaction by filling in the necessary reagents.

asked Feb 20, 2014 by sreemathi.v

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Which of the following will not show tautomerism?

asked Feb 20, 2014 by sreemathi.v

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What is the correct name of the following molecule?

asked Feb 20, 2014 by sreemathi.v

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Predict the product in the following : $CH_3CHO+4HCHO\quad\underrightarrow{\text{Conc aq NaOH}}$

asked Feb 20, 2014 by sreemathi.v

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What would be the product of the following reaction?

asked Feb 20, 2014 by sreemathi.v

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In the following reaction what is X?

asked Feb 20, 2014 by sreemathi.v

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What is X in the following reaction?

asked Feb 20, 2014 by sreemathi.v

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What is X in the below reaction?

asked Feb 20, 2014 by sreemathi.v

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Select the molecule which has only one $\pi$-bond

asked Feb 20, 2014 by sreemathi.v

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The decreasing order of $K_{eq}$ values in HCN addition to following aldehydes is

asked Feb 20, 2014 by sreemathi.v

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Predict the product in the following reaction

asked Feb 20, 2014 by sreemathi.v

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A right angle prism $(45^{\circ} - 90^{\circ}- 45^{\circ})$ of refractive index n has a plate of refractive index $n_1\;( n_1 < n ) $ to its diagonal wall. The assembly is in air. A ray is incident at AB . Then the angle of incidence at AB for which the ray strikes the diagonal face at critical angle is :-

asked Feb 20, 2014 by meena.p

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Which of the following will be a best hydride donor?

asked Feb 20, 2014 by sreemathi.v

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In YDSE intensity at a point is $\bigg (\large\frac{1}{4} \bigg) $ of maximum intensity. Angular position of this point is :

asked Feb 20, 2014 by meena.p

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A solid metallic sphere of radius a is surrounded by a conducting spherical shell of radius b $\;(b >a)\;$ . The solid sphere is given a charge Q . Potential at the surface of the solid sphere is $\;V_{a}\;$ and at the surface of spherical shell is $\;V_{b}\;$. If we put -4Q charge on the shell the potential differance between the sphere and shell becomes $\;\bigtriangleup V\;.$ Now we earthed the outer shell and the charge on the ouer shell is $\;q_{1}\;$.Now we removed the earthing connection from the shell and earthed the inner solid sphere. Charge on solid sphere becomes $\;q_{2}\;$. Answer the following question based on the passage.Now if we connected the shell and solid sphere after removing earthing from the solid sphere charge on outer surface of shell becomes.

asked Feb 20, 2014 by yamini.v

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The cannizzaro reaction is given below :

asked Feb 20, 2014 by sreemathi.v

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A solid metallic sphere of radius a is surrounded by a conducting spherical shell of radius b $\;(b >a)\;$ . The solid sphere is given a charge Q . Potential at the surface of the solid sphere is $\;V_{a}\;$ and at the surface of spherical shell is $\;V_{b}\;$. If we put -4Q charge on the shell the potential differance between the sphere and shell becomes $\;\bigtriangleup V\;.$ Now we earthed the outer shell and the charge on the ouer shell is $\;q_{1}\;$.Now we removed the earthing connection from the shell and earthed the inner solid sphere. Charge on solid sphere becomes $\;q_{2}\;$. Answer the following question based on the passage. $\;q_{2}\;$ is

asked Feb 20, 2014 by yamini.v

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In YDSE if the source consists of two wave lengths $\lambda_1=4000 \;a^{\circ}$ and $\lambda _2 =4002\;A^{\circ}$ . Find the distance from centre where fringes disappear if $d= 1\;cm; D=1\;m$

asked Feb 20, 2014 by meena.p

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Predict the product in the following reaction

asked Feb 20, 2014 by sreemathi.v

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