MCQOPTIONS
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MCQOPTIONS
This section includes 22 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Energy of electron in a orbit of H-atom is [RPET 2000] |
| A. | Positive |
| B. | Negative |
| C. | Is twice the outside value |
| D. | Nothing can be said |
| Answer» C. Is twice the outside value | |
| 2. |
Number of spectral lines in hydrogen atom is [CPMT 1997] |
| A. | 3 |
| B. | 6 |
| C. | \[\frac{I}{zmt}=\text{constant}\] |
| D. | Infinite |
| Answer» E. | |
| 3. |
In Rutherford scattering experiment, what will be the correct angle for \[\alpha \] scattering for an impact parameter b = 0 [CBSE PMT 1994; JIPMER 2000] |
| A. | \[{{90}^{o}}\] |
| B. | \[{{270}^{o}}\] |
| C. | 0.8 gm |
| D. | \[{{180}^{o}}\] |
| Answer» E. | |
| 4. |
Ionization energy of hydrogen is 13.6 eV. If \[h=6.6\times {{10}^{-34}}J-\]sec, the value of R will be of the order of [RPMT 1997] |
| A. | \[{{10}^{10}}{{m}^{-1}}\] |
| B. | \[{{10}^{7}}{{m}^{-1}}\] |
| C. | If assertion is true but reason is false. |
| D. | \[{{10}^{-7}}{{m}^{-1}}\] |
| Answer» C. If assertion is true but reason is false. | |
| 5. |
The extreme wavelengths of Paschen series are [RPET 1997] |
| A. | \[0.365\mu m\]and \[0.565\mu m\] |
| B. | \[0.818\mu m\]and \[1.89\mu m\] |
| C. | If assertion is true but reason is false. |
| D. | \[2.27\mu m\]and \[7.43\mu m\] |
| Answer» C. If assertion is true but reason is false. | |
| 6. |
Which one of these is non-divisible [KCET 1994] |
| A. | Nucleus |
| B. | Photon |
| C. | If assertion is true but reason is false. |
| D. | Atom |
| Answer» C. If assertion is true but reason is false. | |
| 7. |
The wavelength of the first line of Balmer series is \[6563\ {AA}\]. The Rydberg constant for hydrogen is about [MP PMT/PET 1998] |
| A. | \[1.09\times {{10}^{7}}per\ m\] |
| B. | \[1.09\times {{10}^{8}}per\ m\] |
| C. | If assertion is true but reason is false. |
| D. | \[1.09\times {{10}^{5}}per\ m\] |
| Answer» B. \[1.09\times {{10}^{8}}per\ m\] | |
| 8. |
In a hydrogen atom, which of the following electronic transitions would involve the maximum energy change [MP PET 1997] |
| A. | From n = 2 to n = 1 |
| B. | From n = 3 to n = 1 |
| C. | If assertion is true but reason is false. |
| D. | From n = 3 to n = 2 |
| Answer» C. If assertion is true but reason is false. | |
| 9. |
If the ionisation potential of helium atom is 24.6 volt, the energy required to ionise it will be [MP PMT 1996] |
| A. | 24.6 eV |
| B. | 24.6 V |
| C. | If assertion is true but reason is false. |
| D. | 13.6 eV |
| Answer» B. 24.6 V | |
| 10. |
Which of the following statements about the Bohr model of the hydrogen atom is false [MP PMT 1995] |
| A. | Acceleration of electron in n = 2 orbit is less than that in n = 1 orbit |
| B. | Angular momentum of electron in n = 2 orbit is more than that in n = 1 orbit |
| C. | If assertion is true but reason is false. |
| D. | Potential energy of electron in n = 2 orbit is less than that in n = 1 orbit |
| Answer» E. | |
| 11. |
Figure shows the energy levels P, Q, R, S and G of an atom where G is the ground state. A red line in the emission spectrum of the atom can be obtained by an energy level change from Q to S. A blue line can be obtained by following energy level change [MP PMT 1994] |
| A. | P to Q |
| B. | Q to R |
| C. | 150 W |
| D. | R to G |
| Answer» E. | |
| 12. |
The ratio of the energies of the hydrogen atom in its first to second excited state is [CPMT 1978] |
| A. | 1/ 4 |
| B. | 4/9 |
| C. | 500 nm |
| D. | 4 |
| Answer» D. 4 | |
| 13. |
The radius of electron's second stationary orbit in Bohr's atom is R. The radius of the third orbit will be [EAMCET 1992; DPMT 1999] |
| A. | 3 R |
| B. | 2.25 R |
| C. | 6.2 ´ 108 |
| D. | \[\frac{R}{3}\] |
| Answer» C. 6.2 ´ 108 | |
| 14. |
Radius of first Bohr orbit is r. What is the radius of 2nd Bohr orbit? [BHU 2005] |
| A. | 8r |
| B. | 2r |
| C. | 64000 bits/sec |
| D. | \[2\sqrt{2r}\] |
| Answer» D. \[2\sqrt{2r}\] | |
| 15. |
If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of \[L{{i}^{++}}\] is [AIEEE 2003] |
| A. | 122.4 eV |
| B. | 30.6 eV |
| C. | 8 to 88 MHz |
| D. | 3.4 eV |
| Answer» C. 8 to 88 MHz | |
| 16. |
The ratio of speed of an electron in ground state in Bohrs first orbit of hydrogen atom to velocity of light in air is [MH CET 2002] |
| A. | \[\frac{{{e}^{2}}}{2{{\varepsilon }_{0}}hc}\] |
| B. | \[\frac{2{{e}^{2}}{{\varepsilon }_{0}}}{hc}\] |
| C. | 270 W |
| D. | \[\frac{2{{\varepsilon }_{0}}hc}{{{e}^{2}}}\] |
| Answer» B. \[\frac{2{{e}^{2}}{{\varepsilon }_{0}}}{hc}\] | |
| 17. |
An electron jumps from 5th orbit to 4th orbit of hydrogen atom. Taking the Rydberg constant as \[{{10}^{7}}\] per metre. What will be the frequency of radiation emitted [Pb. PMT 2001] |
| A. | \[6.75\times {{10}^{12}}\,Hz\] |
| B. | \[6.75\times {{10}^{14}}\,Hz\] |
| C. | Frequency modulation |
| D. | None of these |
| Answer» D. None of these | |
| 18. |
Radius of the first orbit of the electron in a hydrogen atom is 0.53 Å. So, the radius of the third orbit will be [Kerala (Engg.) 2001] |
| A. | 2.12 Å |
| B. | 4.77 Å |
| C. | \[\frac{1}{1490},\frac{1}{1510}\] |
| D. | 1.59 Å |
| Answer» C. \[\frac{1}{1490},\frac{1}{1510}\] | |
| 19. |
The ratio of the speed of the electron in the first Bohr orbit of hydrogen and the speed of light is equal to (where e, h and c have their usual meanings) [MP PMT 2000] |
| A. | \[2\pi hc/{{e}^{2}}\] |
| B. | \[{{e}^{2}}h/2\pi c\] |
| C. | Is highly directional |
| D. | \[2\pi {{e}^{2}}/hc\] |
| Answer» E. | |
| 20. |
In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in \[n=2\] and \[n=1\] orbits is [EAMCET (Engg.) 2000] |
| A. | 2 : 1 |
| B. | 4 : 1 |
| C. | Horizontal type |
| D. | 16 : 1 |
| Answer» D. 16 : 1 | |
| 21. |
In hydrogen atom, if the difference in the energy of the electron in \[n=2\] and \[n=3\] orbits is E, the ionization energy of hydrogen atom is [EAMCET (Med.) 2000] |
| A. | 13.2 E |
| B. | 7.2 E |
| C. | m1 = m2 |
| D. | 3.2 E |
| Answer» C. m1 = m2 | |
| 22. |
What will be the angular momentum of a electron, if energy of this electron in H-atom is 1.5eV (in J-sec) [RPMT 2000] |
| A. | \[1.05\times {{10}^{-34}}\] |
| B. | \[2.1\times {{10}^{-34}}\] |
| C. | If assertion is true but reason is false. |
| D. | \[-2.1\times {{10}^{-34}}\] |
| Answer» D. \[-2.1\times {{10}^{-34}}\] | |