The energy of a hydrogen atom in the ground state is -13.6 eV. The energy of a ${\mathrm{He}}^{+}$ ion in the first excited state will be

(a) -13.6 eV

(b) -27.2 eV

(c) -54.4 eV

(d) -6.8 eV

Concept Questions :-

Bohr's model of atom
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An alpha nucleus of energy $\frac{1}{2}m{v}^{2}$ bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to

(a) $\frac{1}{Ze}$                              (b) ${v}^{2}$

(c) $\frac{1}{m}$                               (d) $\frac{1}{{v}^{4}}$

Concept Questions :-

Various atomic model
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The electron in the hydrogen atom jumps from excited state $\left(n=3\right)$ to its ground state $\left(n=1\right)$ and the photons thus emitted irradiate a photosensitive material. If the work function of the material is  the stopping potential is estimated to be (the energy of the electron in the nth state ${\mathrm{E}}_{\mathrm{n}}=-\frac{13.6}{{\mathrm{n}}^{2}}\mathrm{eV}$)

1.                                                2.

3.                                               4.

Concept Questions :-

Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In a Rutherford scattering experiment when a projectile of charge ${Z}_{1}$ and mass ${M}_{1}$ approaches a target nucleus of charge ${Z}_{2}$ and mass ${M}_{2},$ the distance of closest approach is ${r}_{0}$. The energy of the projectile is

(a) directly proportional to ${M}_{1}×{M}_{2}$

(b) directly proportional to ${Z}_{1}{Z}_{2}$

(c) inversely proportional to ${Z}_{1}$

(d) directly proportional to mass ${M}_{1}$

Concept Questions :-

Various atomic model
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The ionization energy of the electron in the hydrogen atom in its ground state is 13.6 eV. The atoms are excited to higher energy levels to emit radiations of 6 wavelengths. Maximum wavelength of emitted radiation corresponds to the transition between

(a) n=3 to n=2 states

(b) n=3 to n=1 states

(c) n=2 to n=1 states

(d) n=4 to n=3 states

Concept Questions :-

Spectral series
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The ground state energy of hydrogen atom is -13.6 eV. When its electron is in the first excited state, its excitation energy is:

(a) 3.4 eV                                (b) 6.8 eV

(c) 10.2 eV                              (d) zero

Concept Questions :-

Bohr's model of atom
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Difficulty Level:

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of:

(a) excitation of electrons in the atoms

(b) collision between the atoms of the gas

(c) collisions between the charged particles emitted from the cathode and the atoms of the gas

(d) collision between different electrons of the atoms of the gas

Concept Questions :-

X-ray
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The ratio of momenta of an electron and an $\mathrm{\alpha }$- particle which are accelerated from rest by a potential difference of 100 V is

1. 1                              2. $\sqrt{\frac{2{\mathrm{m}}_{\mathrm{e}}}{{\mathrm{m}}_{\mathrm{\alpha }}}}$
3. $\sqrt{\frac{{\mathrm{m}}_{\mathrm{e}}}{{\mathrm{m}}_{\mathrm{\alpha }}}}$                      4. $\sqrt{\frac{{\mathrm{m}}_{\mathrm{e}}}{2{\mathrm{m}}_{\mathrm{\alpha }}}}$

Concept Questions :-

Various atomic model
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When subjected to a transverse electric field, cathode rays move:

(c) Along a hyperbolic path

(d) Along a circular path

Concept Questions :-

Various atomic model
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The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally by
(a) Planck                   (b) J.J. Thomson
(c) Einstein                 (d) Millikan

Concept Questions :-

Various atomic model