Question

The quantum numbers $+1/2$ and $-1/2$ for the electron spin represent:

• A. Rotation of the electron in clockwise and anticlockwise direction respectively
• B. Rotation of the electron in anti-clockwise 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: (A), (D)

The correct options are
A Rotation of the electron in clockwise and anticlockwise direction respectively
D Two quantum mechanical spin states which have no classical analogue

Just like the earth rotates around its axis, the electron spins about its axis either clockwise or anti-clockwise manner. The two types of rotation are $+\frac{1}{2}$ and $-\frac{1}{2}$. These two quantum mechanical spin states which have no classical analogue.

Hence, the correct options are $A$ and $D$