A polariod (I) is placed in front of a monochromatic source. Another polariod (II) is placed in front of this polariod (I) and rotated till no light passes. A third polariod (III) is now placed in between (I) and (II), then

Options

A. when axis of (I) and (III) are parallel then no light emers out of (II)
B. when axis of (II) and (III) are parallel then no light emerges out of (II)
C. When axis of (I), (III) and (II) are non-parallel then light emerges out of (III)
D. For any position of (III) no light emergens out of (II)

Answer

A, C

Explanation

Only on the special cases when the pases axis of (III) is parallel to (I) or (II) there shall be on light emerging. In all other cases there shall be light emerging because the pass axis of (II) is no longer perpendicular to the pass axis of (III).