# Homework Help: Quantum Physics - Waves

1. Feb 10, 2010

### nahanksh

1. The problem statement, all variables and given/known data
The four antennas are arranged in a square with side length d and each of the antennas has an adjustable phase of the radiation emitted. The intensity of radiation emitted by each antenna is I1 with wavelength λ. A receiver is placed at locations A (at the center of the antenna array), B (much farther from the array than d, due east), and C (much farther from the array than d, due south-east). http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys214/oldexams/exam1/sp08/fig5.gif [Broken]

How should the distance d be adjusted so that the maximum possible intensity is received at position B? (Assume φ1 = φ2 = φ3 = φ4 and remember that B is far away.)

2. Relevant equations

3. The attempt at a solution

I am not even getting close to the question..

Could anyone give me a hint or help approach to this question..?

Last edited by a moderator: May 4, 2017
2. Feb 10, 2010

### kuruman

Think constructive and destructive interference.