Atoms: JEE Main Physics Previous Year Questions

453 previous year questions from Atoms. Here are the 25 most important ones; open any question for the correct answer and a full step-by-step solution.

1. $In a hypothetical fission reaction_{92} U^{235} +_{0} n^{1} \to_{56} Y^{141} +_{36} Z^{92} + 3 R The identity of emitted particles (R) is:$
2. $When an electron jumps from the orbit n = 2 to n = 4, then wavelength of the radiations absorbed will be (R is Rydberg's constant)$
3. $In a hydrogen atom the electron makes a transition from (n + 1)^{th} level on the n^{th} level. If n >> 1, the frequency of radiation emitted is pro\dots$
4. $When an electron in Hydrogen atom revolves in stationary orbit, it$
5. $The transition of an electron in hydrogen atom that emits a photon whose wavelength lies in the ultraviolet region of the electromagnetic spectrum is$
6. $Given below are two statements: Statement (I): The dimensions of Planck's constant and angular momentum are same. Statement (II): In Bohr's model electron revolve around\dots$
7. $Speed of an electron in Bohr's 7^{t h} orbit for Hydrogen atom is 3.6 x 1 0^{6} m/s. The corresponding speed of the electron in 3^{r d} orbit, in m/s is:$
8. $When the wavelength of the radiation falling on a metal is changed from 500nm to 200 nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The\dots$
9. $Considering the Bohr's model of hydrogen atom, the ratio of velocities of electrons orbiting in the 4^{th} orbit to that in the 9^{th} orbit is$
10. $Substance A has atomic mass number 16 and half life of 1 day. Another substance B has atomic mass number 32 and half life of \frac{1}{2} day. If both A and B simultane\dots$
11. $The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be$
12. $The ratio of the radii of the nuclei_{13} Al^{27} and_{52} T e^{125} approximately$
13. $The radius of 2^{nd} orbit of He^{+} of Bohr's model is r_{1} and that of fourth orbit of Be^{3 +} is represented as r_{2} . No\dots$
14. $Electrons used in a electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100kV then the de-Broglie wavelength associated with the ele\dots$
15. $The disintegration energy Q for the nuclear fission of^{235} U \to^{140} Ce +^{94} Zr + n is_______MeV . Given atomic masses of\dots$
16. $The valence electron in alkali metal is a$
17. $Two electrons are moving in orbits of two hydrogen like atoms with speeds 3 \times 10^{5} m / s and 2.5 \times 10^{5} m / s respectively. If the radii of\dots$
18. $_{92}^{238} A \to_{90}^{234} B +_{2}^{4} D + Q In the given nuclear reaction, the approximate amount of energy released will be: [Given, mass of\dots$
19. $Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be :$
20. $If radius of the_{12}^{27} Al nucles is taken to be R_{Al} then the radius of_{53}^{125} Te nucleus is nearly :$
21. $Two radiations of photons energies 1 eV and 2.5 eV, successively illuminate a photosensitive metallic surface of work function 0.5 eV. The ratio of the maximum speeds of\dots$
22. $The shortest wavelength in Balmer series of hydrogen atom spectrum is approximately equal to (use R_{H} = 1.097 \times 10^{7} m^{- 1})$
23. $The threshold frequency for a photosensitive metal is 3.3 \times 10^{14} Hz . If light of frequency 8.2 \times 10^{14} Hz is incident on\dots$
24. $The total energy of an electron in the first excited state of hydrogen atom is about - 3.4 eV . Its kinetic energy in this state is$
25. $In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is$

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Atoms: JEE Main Physics Previous Year Questions

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