Question

sᴛᴀᴛᴇ ᴛʜᴇ ʀᴇᴀsᴏɴ, ᴡʜʏ ᴛᴡᴏ ɪɴᴅᴇᴘᴇɴᴅᴇɴᴛ sᴏᴜʀᴄᴇs ᴏғ ʟɪɢʜᴛ ᴄᴀɴɴᴏᴛ ʙᴇ ᴄᴏɴsɪᴅᴇʀᴇᴅ ᴀs ᴄᴏʜᴇʀᴇɴᴛ sᴏᴜʀᴄᴇs.​

Answer 1

Answer:

Coherent sources are defined as the sources in the which initial phase difference remains constant. In the case of two independent sources, the initial phase difference cannot remain constant because light is emitted due to millions of atoms and their number goes on changing in a quite random manner.

Two independent sources of light cannot be coherent. This is because light is emitted by individual atoms, when they return to ground state. Even the smallest source of light contains billions of atoms which obviously cannot emit light waves in the same phase.