Atoms - Quiz 10

ATOMS QUIZ-10

Dear Readers,

JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

Q1. One of the lines in the emission spectrum of Li⁽²⁺⁾ has the same wavelength as that of the 2nd line of Balmer series in hydrogen spectrum. The electronic transition corresponding to this line is

•  n=4→n=2
•  n=8→n=2
•  n=8→n=4
•  n=12→n=6

Solution

Q2. The wavelength of the first line of Balmer series is 6563 Å. The Rydberg’s constant is

•  1.09×10⁵ per m^(-1)
•  1.09×10⁶ per m^(-1)
•  1.097×10⁷ per m^(-1)
•  1.09×10⁸ per m^(-1)

Solution

Q3. A hydrogen atom and a Li⁽⁺⁺⁾ ion are both in the second excited state. If l_H and l_LI are their respective electronic angular momenta, and E_H and E_Li their respective energies, then

•   l_H<l_LI and |E_H |>|E_LI |
•  l_H=l_LI and |E_H | < |E_LI |
•  l_H=l_LI and |E_H |>|E_LI |
•  l_H < l_LI and |E_H |<|E_LI |

Solution

Q4. Given: mass number of gold = 197, density of gold= 19.7 g cm^(-3), Avogadro’s number =6×10²³. The radius of the gold atom is approximately:

•  1.5×10^(-8) m
•  1.5×10^(-9) m
•  1.5×10^(-10) m
•  1.5×10^(-12) m

Solution
(c)

Q5. Magnetic field at the center (at nucleus) of the hydrogen-like atoms (atomic number =z) due to the motion of electron in n^th orbit is proportional to

•  n³/z⁵
•  n⁴/z
•  z²/n³
•  z³/n⁵

Solution

Q6. The recoil speed of a hydrogen atom after it emits a photon in going from n=5 state to n=1 state is

•  4.718 ms^(-1)
•  7.418 ms^(-1)
•  4.178 ms^(-1)
•  7.148 ms^(-1)

Solution

Q7. The wavelength K_α of X-rays produced by the X-ray tube is 0.76 Å. The atomic number of the node material of the tube is

•  30
•  40
•  50
•  60

Solution

Q8. The force acting on the electron in a hydrogen atom depends on the principal quantum number as

•  F∝n²
•  F∝1/n²
•  F∝n⁴
•  F∝1/n⁴

Solution

Q9. As the quantum number increases, the difference of energy between conservative energy levels:

•  Decreases
•  Increases
•  First decreases and then increases
•  Remain the same

Solution

Q10. If 10,000 V are applied across an X-ray tube, find the ratio of wavelength of the incident electrons and shortest wavelength of X-ray coming out of the X-ray tube, given e/m, of electron =1.8×10¹¹ C kg^(-1)

•  1:10
•  10:1
•  5:1
• 1:5

Solution