The median cost of internet on its own is $81/mo. The average internet speed in the U.S. These levels exceed average residential power-frequency magnetic fields in homes, which are about 0.07 μT (0.7 mG) in Europe and 0.11 μT (1.1 mG) in North America. In a residential setting, one study reported "limited evidence of carcinogenicity in humans and less than sufficient evidence for carcinogenicity in experimental animals", in particular, childhood leukemia, what is electric cable associated with average exposure to residential power-frequency magnetic field above 0.3 μT (3 mG) to 0.4 μT (4 mG). The opinion also limited the voltage of new transmission lines built in New York to 345 kV. Some studies failed to find any link between living near power lines and developing any sickness or diseases, such as cancer. A 1997 study reported no increased risk of cancer or illness from living near a transmission line. To reduce the risk of users accidentally touching energized conductors and thereby experiencing electric shock, plug and socket systems often incorporate safety features in addition to the recessed contacts of the energized socket. Since 1934, the contacts of a socket have been specified in terms of the pins of the plug, rather than by specifying the contact dimensions.

The first British standard for domestic three-pin plugs was BS 317 Hand-Shield and Side Entry Pattern Three-Pin Wall Plugs and Sockets (Two Pin and Earth Type) published in 1928. This was superseded in 1930 by BS 372 Side-Entry Wall Plugs and Sockets for Domestic Purposes Part II which states that there are only minor alterations from BS 317. In 1934, BS 372 Part II was in turn superseded by the first edition of BS 546 Two-Pole and Earthing-Pin Plugs and Socket Outlets. BS 1363, 13 A plugs socket-outlets adaptors and connection units is a British Standard which specifies the most common type of single-phase AC power plugs and sockets that are used in the United Kingdom. September 1995: BS 1363-3:1995 "13 A plugs socket-outlets adaptors and connection units - Part 3: Specification for adaptors" published. February 1995: BS 1363-1:1995 "13 A plugs socket-outlets adaptors and connection units - Part 1: Specification for rewirable and non-rewirable 13 A fused plugs" published. Modern British sockets for domestic use are normally manufactured as single or double units with an integral face plate and are designed to fit standard mounting boxes. There were concerns that consumer safety was compromised by the substantial quantity of counterfeit and unsafe electrical plugs and sockets being placed on the UK market and also by the provision of electrical equipment without an appropriate means to connect it to the mains supply in the consumer's home.

Neutral is usually at or very near to earth potential, being earthed either at the substation or at the service entrance (neutral-to-earth bonding is not permitted in the distribution board/consumer unit). BS 1363 sockets must have shutters on the line and neutral contacts to prevent the insertion of a foreign object into the socket. This is checked by means of the use of various gauges which are specified in the standard; these gauges ensure that the socket contacts are correctly positioned and make effective and secure contact with the plug pins. Differences between BS4573 Type C and Europlug Type C. The BS4573 plug has round 5.1mm contacts, spacing 16.7mm. The Europlug has 4mm contacts, spacing 19mm. In order to plug a Europlug into a BS4573 socket, an adapter is required. The plug and socket replaced the BS 546 plug and socket, which are still found in old installations or in special applications. The world’s first electronic television was created by a 21 year old inventor named Philo Taylor Farnsworth.

Campbell-Swinton - combined a cathode ray tube with a mechanical scanning system to create a totally new television system. Between 1926 and 1931, mechanical television inventors continued to tweak and test their creations. Holland, Steve; Mikkelsen, Randall (April 8, 2009). "UPDATE 2-US concerned power grid vulnerable to cyber-attack". Shiels, Maggie (April 9, 2009). "Spies 'infiltrate US power grid'". Rapid devices - which can top up a car battery from empty to 80 per cent in around half an hour - make up just over a quarter of the 1,222 additional devices fitted. On special order, three-phase service and/or higher voltages can be provided for specific customers. A plug therefore does not contain components which modify the electrical output from the electrical input (except where a switch or fuse is provided as a means of disconnecting the output from input). In the United Kingdom and in Ireland, this system is usually referred to simply as a "13 amp plug" or a "13 amp socket". 1999. BS 546 is also the precursor of current Indian and South African plug standards. These were usually sold as a mating pair, but gradually de facto and then official standards arose to enable the interchange of compatible devices.