A clump of charged particles moving in circular motion emits em radiation. But if I go on increasing no. of charged particles till the time the system becomes current in circular path, then since each particle is having same acceleration and velocity, the current will be uniform. So, now the system becomes uniform loop of current. Now the electromagnetic field created by uniform loop of current doesn't change w.r.t. time, so this system won't emit em radiation. But, if I consider loop of current system as ,say, 5 clumps of charged particles, then each clump emits em radiation. Since the net radiation is zero, does it mean that radiation created by clumps get canceled among themselves? Each charged particle in the loop emits em radiation. Radiation emitted by one particle gets canceled by radiation emitted by another particles using superposition principle. Is this correct? But, how to understand this thing in photon picture? Each charged particle emits em radiation.⇒ Each charged particle emits photons. Photons emitted by one particle doesn't get canceled by photons emitted by another particles . Since the net radiation is zero, total no. of photons is also 0. How to understand this?