Physics - Atoms - Quiz-1

Orbital acceleration of electron is

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$\frac{n^{2} h^{2}}{4 π^{2} m^{2} r^{3}}$
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$\frac{n^{2} h^{2}}{4 n^{2} r^{3}}$
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$\frac{4 n^{2} h^{2}}{π^{2} m^{2} r^{3}}$
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$\frac{4 n^{2} h^{2}}{4 π^{2} m^{2} r^{3}}$

which of the following is positively charged?

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$α - particles$
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$β - particles$
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$γ - rays$
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$X - rays$

The ratio of minimum to maximum wavelength in Balmer series is

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5 : 9
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5 : 36
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1 : 4
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3 : 4

Ionisation potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be:

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two
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three
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four
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one

The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

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I
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II
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III
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IV

The kinetic energy of the electron in an orbit of radius r in the hydrogen atom is (e = electronic charge)

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$\frac{k e^{2}}{r^{2}}$
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$\frac{k e^{2}}{2 r}$
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$\frac{k e^{2}}{r}$
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$\frac{k e^{2}}{2 r^{2}}$

Whenever a hydrogen atom emits a photon in the Balmer series:

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it may emit another photon in the Balmer series.
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it must emit another photon in the Lyman series.
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it may emit another photon in the Paschen series.
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it need not emit any more photon.

The ionisation potential of hydrogen atom is

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13.60 volt
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8.24 volt
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10.36 volt
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14.24 bolt

Which source is associated with a line emission spectrum?

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Electric fibre
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Neon street Sign
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Red traffic light
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Sun

Frequency of the series limit of Balmer series of hydrogen atom in terms of Rydberg constant R and velocity of light C is:

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$\frac{R C}{4}$
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RC
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$\frac{4}{R C}$
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4RC

Consider the spectral line resulting from transition n = 2 to n = 1 in the atoms and ions given below. The shorterst wavelength is given by

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Hydrogen atom
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Deuterium
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Singly ionised helium
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Doubly ionised lithium

An $α -$ particle of energy 5 MeV is scattered through $180 °$ by a fixed uranium nucleus. The distance of closest approach is of the order

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$10^{- 10} m$
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$10^{- 13} m$
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$10^{- 14} m$
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$10^{- 16} m$

Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model:

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13.6 eV
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0.65 eV
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1.9 eV
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11.1 eV

The energy of an electron in an excited hydrogen atom is -3.4 eV. Its angular momentum will be: (h = 6.626 $\times$ 10^-34 J-s)

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1.11 $\times$ 10³⁴ J s
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1.51 $\times$ 10^-31 J s
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2.11 $\times$ 10^-34 J s
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3.72 $\times$ 10^-34 J s

As per the Bohr model, the minimum energy (in eV) required to remove the electron from the ground state of double ionized lithium ion (Z=3) is:

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1.51
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13.6
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40.8
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122.4

The wavelength of K_a X-rays produced by an X-ray tube is 0.76 $\overset{\circ}{A}$ . Find the atomic number of the anode material of the tube?

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41
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30
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20
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10

According to Bohr's theory the moment of momentum of an electron revolving in second orbit of hydrogen atom will be [MP PET 1999; KCET 2003; VITEEE 2006]

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2 $πh$
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$πh$
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$\frac{h}{π}$
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$\frac{2 h}{π}$

The ionisation energy of a hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponding to a transition between the 3rd and 4th orbit is: [1992]

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3.40 eV
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1.51 eV
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0.85
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0.66 eV

The ratio of the energies of the hydrogen atom in its first to second excited states is

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$\frac{1}{4}$
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$\frac{4}{9}$
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$\frac{9}{4}$
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4

Energy levels A, B, C of a certain atom correspond to increasing values of energy i.e. $E_{A} < E_{B} < E_{C} .$ If $λ_{1}, λ_{2}, λ_{3}$ are the wavelengths of the radiation corresponding to the transitions C to B, B to A and C to A respectively, which of the following relation is correct?

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$λ_{3} = λ_{1} + λ_{2}$
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$λ_{3} = \frac{λ_{1} λ_{2}}{λ_{1} + λ_{2}}$
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$λ_{1} + λ_{2} + λ_{3} = 0$
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$λ_{3}^{2} = λ_{1}^{2} + λ_{2}^{2}$

In the Rutherford scattering experiment, what will be the correct angle for $\propto$ -scattering for an impact parameter, b = 0?

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$90^{\circ}$
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$270^{\circ}$
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$0^{\circ}$
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$180^{\circ}$

The velocity of the electron in the ground state (H - atom) is

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$2.18 \times 10^{5} m / s$
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$2.18 \times 10^{6} m / s$
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$2.18 \times 10^{7} m / s$
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$2.18 \times 10^{8} m / s$

The element which has K $α$ X-ray line whose wavelength is 0.18 nm is:

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Cobalt
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Xenon
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Copper
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Iron

Calculate the highest frequency of the emitted photon in the Paschen series of spectral lines of the Hydrogen atom:

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$3.7 \times 10^{14} H z$
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$9.1 \times 10^{15} H z$
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$10.23 \times 10^{14} H z$
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$29.7 \times 10^{15} H z$

The energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. The energy (in eV) required to remove both the electrons from a neutral helium atom is:

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38.2
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49.2
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51.8
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79.0

Which of the following transitions gives photon of maximum energy?

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n = 1 to n = 2
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n = 2 to n = 1
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n = 2 to n = 6
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n = 6 to n = 2

Hydrogen atoms are excited from ground state of the principal quantum number 4. Then, the number of spectral lines observed will be

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3
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6
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5
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2

When electron jumps from n = 4 to n = 2 orbit, we get [2000]

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second line of Lyman series
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second line of Balmer series
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second line of Paschen series
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an absorption line of Balmer series

The spectrum obtained from a sodium vapour lamp is an example of

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band spectrum
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continuous spectrum
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emission spectrum
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absorption spectrum

The radius of hydrogen atom in its ground state is $5.3 \times 10^{- 11} m .$ After collision with an electron, it is found to have a radius of 21.2 $\times 10^{- 11}$ m. What is the principal quantum number n of the final state of the atom? [1994]

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n = 4
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n = 2
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n = 16
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n = 3

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Practice Physics Quiz Questions and Answers

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Practice Physics Quiz Questions and Answers

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