The FCC required operators to black out programming that comes in from distant markets and duplicates a local station’s own programming (if the local station demanded it). 1949: The FCC adopted the Fairness Doctrine, which made broadcasters responsible for seeking out and presenting all sides of an issue when covering controversy. This type of charging cable connects the electric vehicle and charging station. 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. This type of cable is basically used for the telephone cables and the resistance can be measured by the number of wires used. Electricity is transmitted at high voltages to reduce the energy loss due to resistance that occurs over long distances. The lossless line approximation is the least accurate; it is typically used on short lines where the inductance is much greater than the resistance. Copper was sometimes used for overhead transmission, but aluminum is lighter, what is electric cable reduces yields only marginally and costs much less.

The most commonly used conductors are copper and aluminum. Based on the National Electric Code’s (NEC) technical definition, it is "a factory assembly of one or more insulated circuits enclosed in an armor of interlocking metal tape, or smooth or corrugated metallic sheath." Standard ones usually contain three connectors made of copper or aluminum. GB Patent 294,689: "Improvements in or in connection with Plug and Socket Connectors for Electric Circuits". Different classes of loads (for example, lighting, fixed motors, and traction/railway systems) required different voltages, and so used different generators and circuits. A wide area synchronous grid, known as an interconnection in North America, directly connects generators delivering AC power with the same relative frequency to many consumers. Efficient long-distance transmission of electric power requires high voltages. Overhead transmission wires depend on air for insulation, requiring that lines maintain minimum clearances. High-voltage overhead conductors are not covered by insulation. Note that on this particular pole, the two conductors of one audio pair are transposed.

• In such a way, each wire is closer to the noise source for half of the time and farther away for the other half i.e. in one twist one wire is closer to the noise source and the other is farther; in next twist the reverse is true. The wire length is usually between 1000 and 1500 metres long, depending on the temperature ranges. The wire must be able to carry the current (several thousand amps), remain in line with the route, withstand wind (in Hong Kong typhoon winds can reach 200 km/h), extreme cold and heat and other hostile weather conditions. Adverse weather conditions, such as high winds and low temperatures, interrupt transmission. Underground cables take up no right-of-way, have lower visibility, and are less affected by weather. Bundle conductors are used at high voltages to reduce energy loss caused by corona discharge. Wind speeds as low as 23 knots (43 km/h) can permit conductors to encroach operating clearances, resulting in a flashover and loss of supply.

Thus, multiple parallel cables (called bundle conductors) are used for higher capacity. The conductors' mutual inductance is partially dependent on the physical orientation of the lines with respect to each other. Faults in buried transmission lines take longer to locate and repair. By 1914, fifty-five transmission systems operating at more than 70 kV were in service. More appropriate lower-capacity fuses are now supplied with some plugs instead. Underground transmission is more common in urban areas or environmentally sensitive locations. Underground power transmission has a significantly higher installation cost and greater operational limitations, but lowers maintenance costs. A second set of magnets restores the power immediately after the neutral section has been passed. The tendency of return currents to wander away from the running rails into the ground can set up electrolysis with water pipes and similar metallics. Since the pantograph is usually the single point power contact for the locomotive or power car, it must maintain good contact under all running conditions.