question_answer

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is\[\pi /2\] at point A and n at point B. Then the difference between the resultant intensities at\[\pi \] and B is

A) \[2I\]

B) \[4I\]

C) \[5I\] 

D) \[7I\]