Chapter 18 – Atoms and Nuclei
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Surface of certain metal is first illuminated with light of wavelength λ1=350nm and then, by light of wavelength λ2=540 nm. It is found that the maximum speed of the photo electrons in the two cases differ by a factor of 2. The work function of the metal (in eV) is close to : (Energy of photon = 1240/λ(innm)eV)
28
Nov
Surface of certain metal is first illuminated with light of wavelength λ1=350nm and then, by light of wavelength λ2=540 nm. It is found that the maximum speed of the photo electrons in the two cases differ by a factor of 2. The work function of the metal (in eV) is close to : (Energy of [...]
Half lives of two radioactive nuclei A and B are 10 minutes and 20 minutes, respectively. If, initially a sample has equal number of nuclei, then after 60 minutes, the ratio of decayed numbers of nuclei A and B will be :
28
Nov
Half lives of two radioactive nuclei A and B are 10 minutes and 20 minutes, respectively. If, initially a sample has equal number of nuclei, then after 60 minutes, the ratio of decayed numbers of nuclei A and B will be : Half lives of two radioactive nuclei A and B are 10 minutes and [...]
Consider an electron in a hydrogen atom, revolving in its second excited state (having radius 4.65Å). The de-Broglie wavelength of this electron is :
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Nov
Consider an electron in a hydrogen atom, revolving in its second excited state (having radius 4.65Å). The de-Broglie wavelength of this electron is : Consider an electron in a hydrogen atom revolving in its second excited state (having radius 4.65Å). The de-Broglie wavelength of this electron is : November 28, 2020 Category: Chapter 18 - [...]
The electron in hydrogen atom first jumps from third excited state to second excited state and subsequently to the first excited state. The ratio of the respective wavelength λ1:λ2 of the photons emitted in this process is
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Nov
The electron in hydrogen atom first jumps from third excited state to second excited state and subsequently to the first excited state. The ratio of the respective wavelength λ1:λ2 of the photons emitted in this process is Radiation com in g from transitions n = 2 to n = 1 of hydrogen atoms fall on [...]
An excited He+ ion emits two photons in succession, with wavelengths 108.5 nm and 30.4 nm, in making a transition to ground state. The quantum number n, corresponding to its initial excited state is (for photon of wavelength λ, energy E=1240eV/λ(in nm) ;
28
Nov
An excited He+ ion emits two photons in succession, with wavelengths 108.5 nm and 30.4 nm, in making a transition to ground state. The quantum number n, corresponding to its initial excited state is (for photon of wavelength λ, energy E=1240eV/λ(in nm) ; An excited He+ ion emits two photons in succession corresponding to its [...]
Two radioactive substances A and B have decay constants 5λand λ respectively. At t=0, a sample has the same number of two nuclei. The time taken for the ratio of number of nuclei to become (l/e)^2 will be
28
Nov
Two radioactive substances A and B have decay constants 5λand λ respectively. At t=0, a sample has the same number of two nuclei. The time taken for the ratio of number of nuclei to become (l/e)^2 will be a sample has the same number of two nuclei. The time taken for the ratio of number [...]
In Li++, electron in first Bohr orbit is excited to a level by a radiation of wavelength λ. when the ion gets de excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of λ ? (Given : h = 6.63 × 10^−34Js; c = 3 × 10^8ms^−1) ;
28
Nov
In Li++, electron in first Bohr orbit is excited to a level by a radiation of wavelength λ. when the ion gets de excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of λ ? (Given : h = 6.63 [...]
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a total of six spectral lines are observed. What is the value of λ ? (Given : h = 6.63 × 10^−34Js; c = 3 × 10^8ms^−1) ; ,
electron in first Bohr orbit is excited to a level by a radiation of wavelength λ. when the ion gets de excited to the ground state in all possible ways (including intermediate emissions) ,
In Li++ ,
Two radioactive materials A and B have decay constants 10λ and λ, respectively. It initially they have the same number of nuclei, then the ratio of the number of nuclei of A to that of B will be 1/e after a time :
28
Nov
Two radioactive materials A and B have decay constants 10λ and λ, respectively. It initially they have the same number of nuclei, then the ratio of the number of nuclei of A to that of B will be 1/e after a time : respectively. It initially they have the same number of nuclei then the [...]
A He+ ion is in its first excited state. Its ionization energy is
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Nov
A He+ ion is in its first excited state. Its ionization energy is A He+ ion is in its first excited state. Its ionization energy is November 28, 2020 Category: Chapter 18 - Atoms and Nuclei , JEE Mains Physics 2002-2019 Solved Video Solutions ,
Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as 660 nm, the wavelength of the 2nd Balmer line (n = 4 to n = 2) will be :
28
Nov
Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as 660 nm, the wavelength of the 2nd Balmer line (n = 4 to n = 2) will be : Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as [...]