Quantum Mechanics Test-15 MCQ

CSIR-JRF/NET Physics

Quantum Mechanics Test-15

Answer all questions                                                                    Time 20 min

                                                                                                               Max 20 marks

1. A  quantum mechanical system containing a large, and possibly infinite, number of degrees of freedom is called ---

(a) electric field                                                 (b)magnetic filed

(c) gravitational field                                       (d) quantum field 

2. Quantum mechanics, in its most general formulation, is a theory  of operators (observables) acting on an abstract  space called----

(a) Lorentz space                                              (b) Reimanian space                      

(c) boson field                                                    (d) Hilbert space*

3. The fundamental observables associated with the motion of a single quantum mechanical particle are  

 (a)E and P operators                                     (b)x and E operators

(c) L and P operators                                       (d)x and P operator*

4.  There are two motivations for studying the many-particle problem. The first is a straightforward need in condensed matter physics, The second is in ----

(a)   meson field theory                                 (b) black body radiation

(c) gluon theory                                            (d) particle physics*

5. If one attempts to include the relativistic rest energy into the Schrodinger equation  the result is either the Klein-Gordon equation  or the ----

 (a) uncertainty equation                              (b) wave function

(c) Delta equation                                        (d) Dirac equation*

6. Orbital angular momentum, which is a generalization of angular momentum in classical mechanics (L=r×p). Then what is the classical analogue of spin angular momentum in quantum mechanics?

 (a) No analogue*                                               (b) linear momentum

 (c) rotationl motion                                         (d) spin momentum

7. The spin of atoms and molecules is the sum of the spins of----------, which may be parallel or antiparallel.

(a) unpaired electrons*                                     (b) paired electrons       

 (c) valence electrons                                    (d) all electrons

8.  The intrinsic magnetic moment μ of a Spin-½ particle with charge q, mass m, and spin angular momentum S, is given by the equation----

(a) μ =g_sq S/(2m)*              (b) ) μ =g_sq S/(m)(c) ) μ =g_sqm S/2m      (d) μ =2g_sqm S/2

9. In the above question g_s is called---

(a) spin g-factor*                 (b) space g-factor(c) Lorentz g-factor      (d) fractional  g-factor

10. The value of spin g-factor is ----

(a) 1*                       (b) 2                                       (c) 2.002319                        (d) 3.00

Answers are marked with a *