1. No category

Kingdom of Saudi Arabia
Ministry of Higher Education
Salman bin Abdul-Aziz University
College of Science and Humanities
Al-Kharj
Department of Physics
The first quarterly exam
First semester for the academic year 1435/1436 H
Phys 4160
Monday, 2/01/1436 H
The time from 11 to 12AM
Student name:
University number:
Dr: H. G. Abdelwahed
Sum
Division No.:
Third Question
Second Question
First Question
4
6
5
15
Exam paper consisting of four pages
15Marks
Answer the Following Questions: Each Questions (15) Marks
(where : R= 1.097 x10-10 m-1 . h = 6.63 x 10-34 j. s , me =9.1 x10-31 kg,
c=3x108 m/s, 0=8.85x10-12 F/m, e=1.6x10-19C.)
Q-1a) Choose the correct answers:
1.
2 Marks
The total energy En of the electron in the nth orbit according to Bohr
theory for hydrogen atom varies with…….
(a) n 2
(b) n
(d) 1/ n 2
(c) n
2. The wavelength of first line in Balmer series of H atom ……., where R
is Rydberg’s constant.
(a )
(d )
1
1
R
1 1
4 9
R
1
6
(b )
1
R
1 1
2 3
(c )
1
R
1 1
1 4
1
4
Q-1b)
Determine the two possible orientation of the spin angular momentum S
with respect to magnetic field.
2
3Marks
Q-2a
Q-2b)
Calculate for hydrogen atom (a) velocity of an electron in ground state;
(b) time taken by the electron to traverse the Bohr s first orbit; (c)
Rydberg’s constant.
Write short notes about atomic Dalton model.
3
4 Marks
2 Marks
Q-3)
0
Prove that radius of Bohr s orbit in ground state of hydrogen atom is 0.5 A .
With our Best wishes
Dr. H. Gomaa
4
4 Marks