Consider telecommunication through optical fibres. Which of the following statements is not true?

Some of the characteristics of an optical fiber are as follows:

(i)         It consists of core made up of glass/silica/plastic with refractive index $n_1$ , which is surrounded by a glass or plastic cladding with   refractive index $n_2(n_2<n_1)$ . The refractive index of cladding can be either changing abruptly or gradually changing (graded index fibre).

(ii)        There is a very little transmission loss through optical fibres

(iii)       There is no interference from stray electric and magnetic fields to the signals through optical fibres.