Four identical monochromatic source A, B, C, D as shown in figure produce waves of the same wavelength `lambda` and are coherent. Two receivers `R_(1)` and `R_(2)` are at great but equal distance from B. The choose the correct statements.

Options

A. the reciver `R_(2)` picks up the larger singal
B. two receiver `R_(!)` and `R_(2)` picks up singals of equal intensity when B is turned off
C. when source D is turned off `R_(2)` picksup larger singal
D. when source B is turned off the singal recevied by `R_(1)` changes

Answer

A, B, C, D

Explanation

(a) for `R_(1)|y_(A)+y_(B)+y_(C )+y_(D)|=0`
`R_(2)|y_(A)+y_(B)+y_(C )+y_(D)|_(max) = 2A`
(b) when B is turned off
`|y_(A)+y_(C )+y_(D)|_("for"R_(1)) = |y_(A)+y_(C )+y_(D)|_("for"R_(2))`
(c ) When D is turned off
`|y_(A)+y_(B)+y_(C )|_("for"R_(2)) = 3|y_(A)+y_(B)+y_(C )|_("for"R_(1))`