An Ideal Polarizer with Its Transmission Axis Rotated $30 ^ { \circ }$

Multiple Choice

An ideal polarizer with its transmission axis rotated $30 ^ { \circ }$ to the vertical is placed in a beam of unpolarized light of intensity $10 \mathrm {~W} / \mathrm { m } ^ { 2 }$ . After passing through the polarizer, what is intensity of the beam?

A) $2.5 \mathrm {~W} / \mathrm { m } ^ { 2 }$
B) $8.7 \mathrm {~W} / \mathrm { m } ^ { 2 }$
C) $5.0 \mathrm {~W} / \mathrm { m } ^ { 2 }$
D) $7.5 \mathrm {~W} / \mathrm { m } ^ { 2 }$
E) $10 \mathrm {~W} / \mathrm { m } ^ { 2 }$