1
JEE Main 2021 (Online) 24th February Evening Shift
MCQ (Single Correct Answer)
+4
-1
According to Bohr's atomic theory :
(A) Kinetic energy of electron is $$ \propto {{{Z^2}} \over {{n^2}}}$$.
(B) The product of velocity (v) of electron and principal quantum number (n), $$'vn' \propto {Z^2}$$.
(C) Frequency of revolution of electron in an orbit is $$ \propto {{{Z^3}} \over {{n^3}}}$$.
(D) Coulombic force of attraction on the electron is $$ \propto {{{Z^3}} \over {{n^4}}}$$.
Choose the most appropriate answer from the options given below :
(A) Kinetic energy of electron is $$ \propto {{{Z^2}} \over {{n^2}}}$$.
(B) The product of velocity (v) of electron and principal quantum number (n), $$'vn' \propto {Z^2}$$.
(C) Frequency of revolution of electron in an orbit is $$ \propto {{{Z^3}} \over {{n^3}}}$$.
(D) Coulombic force of attraction on the electron is $$ \propto {{{Z^3}} \over {{n^4}}}$$.
Choose the most appropriate answer from the options given below :
2
JEE Main 2020 (Online) 5th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
The correct statement about probability density (except at infinite distance from nucleus) is :
3
JEE Main 2020 (Online) 5th September Morning Slot
MCQ (Single Correct Answer)
+4
-1
The difference between the radii of 3rd and 4th
orbits of Li2+ is R1 . The difference between the
radii of 3rd and 4th orbits of He+ is $$\Delta $$R2 .
Ratio $$\Delta $$R1 : $$\Delta $$R2 is :
orbits of Li2+ is R1 . The difference between the
radii of 3rd and 4th orbits of He+ is $$\Delta $$R2 .
Ratio $$\Delta $$R1 : $$\Delta $$R2 is :
4
JEE Main 2020 (Online) 4th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
The shortest wavelength of H atom in the
Lyman series is $$\lambda $$1. The longest wavelength in
the Balmar series of He+ is :
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