Question

166. The quantum numbers +1/2 and -1/2 for the electron spin
represents
(a) rotation of the electron in clockwise and anticlockwise
direction respectively
(b) rotation of the electron in anticlockwise and clockwise
direction respectively
(c) magnetic moment of the electron pointing up and
down respectively
(d) two quantum mechanical spin states which have no
classical analogue.​

Answer 1

Answer:

Option d

Option a and b can never be correct cause the definition of spin quantum no. itself says that it doesn't represents any specific direction of electron.

Option c is of magnetic moment.

Hence the option d cause it say its spin i.e. direction is not defined.