Initially scientists estimated that silica optical bre may reach a 'low loss' attenuation of about 20 dB/ km and now the lowest attenuation reached is

Initially scientists estimated that silica optical fibre may reach a 'low loss' attenuation of about 20 dB/ km and now the lowest attenuation reached is about 0.158 dB/ km. Work out the corresponding attenuation coefficients in 1/ m.