National Physical Laboratory of India users. This process, known as dissemination, is carried out in a number of ways. For applications requiring low levels of uncertainty, there is satellite based dissemination service, which utilizes the Indian national satellite, INSAT. Time is also disseminated through TV, radio, and special telephone services. The caesium atomic clocks maintained at NPL are linked to other such instituted all over the world through a set of global positioning satellites. The unit of electric current, ampere, is realized at NPL by measuring volt and Ohm separately. The uncertainty in measurement of ampere is ± 1 × 10. The standard of temperature
Electrical wiring in the United Kingdom 1, 1.5, 2.5, 4, 6 and 10 mm. Sizes of 1 or 1.5 mm are typically used for 6 or 10 ampere lighting circuits and 2.5 mm for socket circuits. The earthing conductor is uninsulated since it is not intended to have any voltage difference from surrounding earthed articles. Additionally, if the insulation of a or neutral wire becomes damaged, then the wire is more likely to earth itself on the bare earth conductor and in doing so either trip the RCD or burn the fuse out by drawing too much current. Earthing and Bonding are used together to provide