Recent questions tagged medium

The ionization energy of $He^+$ is $19.6\times 10^{-18}J/atom$.Calculate the energy of first stationary state of $Li^{2+}$

asked Jan 15, 2014 by sreemathi.v

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The ionization energy of H atom is $13.6eV$.What will be ionization energy of $He^+$ and $Li^{2+}$ ions?

asked Jan 15, 2014 by sreemathi.v

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A bulb emits light of $\lambda=4500A^{\circ}$ .The bulb is rated as 150watt and 8% of the energy is emitted as light.How many photons are emitted by the bulb per second?

asked Jan 15, 2014 by sreemathi.v

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Iodine molecule dissociates into atoms after absorbing light of 4500$A^{\circ}$ .If one quantum of radiation is absorbed by each molecule,calculate the kinetic energy of iodine atoms (Bond energy of $I_2=240KJmol^{-1}$)

asked Jan 15, 2014 by sreemathi.v

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The number of radial nodes of 3s and 2p orbitals are respectively

asked Jan 15, 2014 by sreemathi.v

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The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom

asked Jan 15, 2014 by sreemathi.v

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The quantum numbers $\large\frac{1}{2}$ and $-\large\frac{1}{2}$ for the electron spin represents :

asked Jan 15, 2014 by sreemathi.v

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If the nitrogen atom had electronic configuration $1s^7$,it would have energy lower than that of normal ground state configuration $1s^22s^22p^3$,because the electrons would be closer to the nucleus.Yet $1s^7$ is not observed because it violates

asked Jan 15, 2014 by sreemathi.v

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Number of nodal plane in px-orbital is

asked Jan 15, 2014 by sreemathi.v

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The wavelength of a golf ball weighing 200g and moving with a speed of 5m/h is of the order :

asked Jan 15, 2014 by sreemathi.v

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The electronic configuration of an element is $1s^2,2s^22p^6,3s^23p^63d^5,4s^1$.This represents its

asked Jan 15, 2014 by sreemathi.v

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The electrons,identified by quantum number n and l,(i) n=4,l=1;(ii) n=4,l=0;(iii) n=3,l=2;(iv) n=3,l=1 can be placed into order of increasing energy,from the lowest to highest,as :

asked Jan 15, 2014 by sreemathi.v

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The energy of an electron in the first orbit of H-atom is -13.6eV.The possible value of excited state for electron in bohr orbit of H atom are :

asked Jan 15, 2014 by sreemathi.v

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The first use of quantum theory to explain the structure of atom was given by

asked Jan 15, 2014 by sreemathi.v

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For a d electron,the orbital angular momentum is :

asked Jan 15, 2014 by sreemathi.v

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Which has maximum number of unpaired electron :

asked Jan 15, 2014 by sreemathi.v

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A 3p-orbital has :

asked Jan 13, 2014 by sreemathi.v

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Calculate the wavelength (in nanometer) associated with a proton moving $1.0\times 10^3ms^{-1}$ (mass of proton=$1.67\times 10^{-27}$kg and $h=6.63\times 10^{-34}Js)$

asked Jan 13, 2014 by sreemathi.v

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In an atom,an electron is moving with a speed of 600m/s with an accuracy of 0.005%.Certainly with which the position of the electron can be located is ($h=6.6\times 10^{-34}kg)m^2s^{-1}$.mass of electron,$e_m=9.1\times 10^{-31}kg)$

asked Jan 13, 2014 by sreemathi.v

1 answer

The ionization enthalpy of hydrogen atom is $1.312\times 10^6\;Jmol^{-1}$.The energy required to excite the electron in the atom from $n=1$ to $n=2$ is

asked Jan 13, 2014 by sreemathi.v

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The "spin-only" magnetic moment [in units of Bohr magneton,$(\mu_B)$] of $Ni^{2+}$ in aqueous solution would be (Atomic no Ni=28)

asked Jan 13, 2014 by sreemathi.v

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If $\overrightarrow v=2\hat i+\hat j-\hat k\:\:and\:\;\overrightarrow w=\hat i+3\hat k$ and $\overrightarrow u$ is a unit vector,then the maximum value of $ [\overrightarrow u\:\overrightarrow v\:\overrightarrow w]$ is ?

asked Jan 13, 2014 by rvidyagovindarajan_1

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The wavelength of the radiations emitted,when in a hydrogen atom electron falls from infinity to stationary state is ($R_H=1.097\times 10^7m^{-1})$

asked Jan 13, 2014 by sreemathi.v

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A thin metal sheet is placed between the plates of a parallel plate capacitor. Its capacitance will

asked Jan 10, 2014 by meena.p

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Three identical metal plates are kept parallel to one another at seperation $d_1\; and\; d_2 $ If both the outer plates are connected to ground and middle plate is given charge q, The charge on right side of middle plate will be :

asked Jan 10, 2014 by meena.p

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A charged particle moves in a circle around an infinite line charge such that center of circle lies on line and line is perpendicular to plane of circle. If r is the radius of circle the velocity of particle will depend on which power of r .

asked Jan 10, 2014 by meena.p

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A conducting spherical shell is earthed. A +ve charge $+q_1$ is placed at its centre and another +ve charge $+q_2$ is placed outside at a distance d from centre . If the conducting spherical shell is not earthed , then force on $q_2$ is:

asked Jan 10, 2014 by meena.p

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A conducting spherical shell is earthed. A +ve charge $+q_1$ is placed at its centre and another +ve charge $+q_2$ is placed outside at a distance d from centre . If the effect of induced charge due to $q_2$ on sphere is ignored. Then coulomb force on $q_2$

asked Jan 10, 2014 by meena.p

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A charge particle of mass 1 kg and charge $ 1 \mu c$ is projected from horizontal ground at an angle $ \theta=45^{\circ}$ with speed $10 ms^{-1}$. In space a horizontal electric field towards the direction of projection $E= 10^{7}NC^{-1}$ exists. The range of projectile is :

asked Jan 10, 2014 by meena.p

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A charge Q is placed at a distance $D( > R)$ above the centre of disk of radius R The magnitude of flux through disk is $\phi$ . Now a hemispherical shell of radius R is put above the disk to form a closed surface. The flux through the closed surface, if direction of area vector along outward normal is +ve, is :

asked Jan 10, 2014 by meena.p

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Two infinite long parallel wires having linear charge densities $\lambda_1\; and\; \lambda_2 $ respectively are placed at a distance R. The force per unit length on wire (1) will be:

asked Jan 10, 2014 by meena.p

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Find the equivalent capacitance between A ans B ,each capacitor having capacitance C.

asked Jan 10, 2014 by meena.p

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If a dielectric slab is inserted in between a capacitor of capacitance C after charging it to a potential V, the net charge on surfaces shown below will be :

asked Jan 10, 2014 by meena.p

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If the plane $x-2y+3z=0$ is rotated through a right angle about its line of intersection with the plane $2x+3y-4z-5=0$, then the eqn. of the plane in its new position is ?

asked Jan 9, 2014 by rvidyagovindarajan_1

1 answer

The angle between the line formed by $3x-7y-5z=1$ and $8x-11y+2z=0$ and the line formed by $5x-13y+3z+2=0$ and $8x-11y+2z=0$

asked Jan 9, 2014 by rvidyagovindarajan_1

1 answer

If a point charge is placed at the centre of closed cylindrical conductor of length l and radius R. the flux through the cylinder will be :

asked Jan 9, 2014 by meena.p

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A circular ring of radius R has charge Q distributed uniformly on it. If a space of radius R, has its centre lying on boundary of the ring, then flux coming out of sphere will be :

asked Jan 9, 2014 by meena.p

1 answer

Ordinary dice are rolled. The probability that at least half of them will show at least 3 is

asked Jan 9, 2014 by thanvigandhi_1

1 answer

Find the wave length of radiation required to excite the electron in ground level of $Li^{++}(z=3)$ to third energy level.Also find the ionization energy of $Li^{2+}$.(R=$1.097\times 10^7m^{-1})$

asked Jan 9, 2014 by sreemathi.v

1 answer

A fair coin is tossed 100 times. The probability of getting tails on odd number of times is

asked Jan 9, 2014 by thanvigandhi_1

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A coin is tossed 7 times. The probability that he wins the toss on more occasions is

asked Jan 9, 2014 by thanvigandhi_1

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In a binomial distribution $B \bigg( n, P = \large\frac{1}{4} \bigg)$ If the probability of at least one success is greater than or equal to $ \large\frac{9}{10}$ then $n$ is greater than

asked Jan 9, 2014 by thanvigandhi_1

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Calculate the wave length of light radiation that would be emitted,when an electron in the fourth Bohr's orbit of $He^+$ ion falls to the second Bohr's orbit.To what transition does this light radiation correspond in the H-atom?

asked Jan 9, 2014 by sreemathi.v

1 answer

A spectral line in the spectrum of $H$-atom has a wave number of $15222.22cm^{-1}$. What transition is responsible for this radiation? (Rydberg constant $R=1.096\times 10^5cm^{-1}$)

asked Jan 9, 2014 by sreemathi.v

1 answer

Mark the correct statements :

asked Jan 9, 2014 by meena.p

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Estimate the wavelength of second line (also called as $\beta$-line) in Balmer series of hydrogen atom

asked Jan 9, 2014 by sreemathi.v

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A hydrogen atom in the ground state is hit by a particle exciting the electron to 4s orbital.The electron then drops to 2s orbital.What is the frequency of radiation emitted and absorbed in the process?

asked Jan 9, 2014 by sreemathi.v

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Determine the frequency of revolution of the electron in $2^{nd}$ Bohr's orbit in hydrogen atom

asked Jan 9, 2014 by sreemathi.v

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Calculate the velocity of electron ejected from platinum surface when radiation of 200nm fall on it. Work function of platinum is 5eV. $(1eV=1.6\times 10^{-19}J$)

asked Jan 9, 2014 by sreemathi.v

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A 100W power source emits green light at a wavelength $\lambda=5000\overset{\circ}{A}$. How many photons per minute are emitted by the source?

asked Jan 9, 2014 by sreemathi.v

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