12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Economics Government Budget and the Economy Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Interface Python with MySQL - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Database Concept - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Data Communication - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Data Structures - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Computer Science Functions - New Previous year Question Papers Study Material - QB365 Set A
Published on: 23/05/2021
QB365 Provides the updated NCERT Exemplar Questions for Class 12, and also provide the detail solution for each and every case study questions. NCERT Exemplar questions are latest updated question pattern from NCERT, QB365 will helps to get more marks in Exams
Download CBSE Class 12th Standard CBSE Physics question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 12th Standard CBSE Physics
Questions + Answers key
Take MCQ Physics Test1.
A set of atoms in an excited state decays
in general to any of the states with lower energy
into a lower state only when excited by an external electric field
all together simultaneously into a lower state
to emit protons only when they collide.
2.
For the ground state, the electron in the H-atom has an angular momentum =h, according to the simple Bohr model. Angular momentum is a vector and hence there will be infinitely many orbits with the vector pointing in all possible directions. In actuality, this is not true,
because only one of these would have a minimum energy
because only one of these would have a minimum energy
angular momentum must be in the direction of spin of electron
because electrons go arround only in horizontal obits.
3.
The simple Bohr model cannot be directly applied to calculate the energy levels of an atom with electrons. This because
of the electrons not being subjects to a central force
of the electrons colliding with each other
of screening effects
the force between the nucleus and an electron will no longer be given by Coulomb's law
4.
Taking the Bohr radius as a0 = 53pm, the radius of Li++ ion its ground state, on the basis of Bohr's model, will be about
53pm
27pm
18pm
13pm
1.
(a)
in general to any of the states with lower energy
2.
(a)
because only one of these would have a minimum energy
3.
(a)
of the electrons not being subjects to a central force
4.
(c)
18pm
12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Computer Science Python Revision Tour I - New Previous year Question Papers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Planning Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Business Environment Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Business Studies Principles of Management Important Questions And Answers Study Material - QB365 Set A
NCERT Books
Syllabus
Exam Pattern
Sample Question Papers
Previous year Question Papers
Important Notes
MCQ Practice test
NCERT Exemplers
Case study Questions
Image Based Questions
Passage based Questions
HOT Questions
Value Based Questions
Model Questions Papers
NCERT ( Book Back ) Questions
Assertion and Reason
Important Questions And Answers
CBSE 12th Standard CBSE Subjects
CBSE Standards
