Why are AC systems preferred over DC systems?

Transmitting electricity over AC links is more efficient, compared to DC transmission, up to a certain distance then DC transmission would be more efficient (hence, HVDC technologies are emerging!)

It`s easy to understand. AC cheaper than DC. In 1880s was "War of Currents" between Edison and Tesla. Tesla has won.

AC transmission is preferred over DC transmission because the power loss is much less as compared to loss in DC.The voltage can be easy step and step down. The DC transmission is less cost effective than AC. Also AC systems require less maintenance than DC systems. 

The power transmission of AC systems is over the DC systems, and for long distance the AC systems show that efficiency of transmission.

AC is preferred because of it's reliability, manageability, maintenance and cost.

    

Due to following reasons, AC systems are preferred over DC systems: 1- It is easy to maintain and change the voltage of AC electricity for transmission and distribution. 2- Plant cost for AC transmission (circuit breakers, transformers etc) is much lower than the equivalent DC transmission c. 3- From power stations, AC is produced so it is better to use AC then DC instead of converting it. When a large fault occurs in a network, it is easier to interrupt in an AC system, as the sine wave current will naturally tend to zero at some point making the current easier to interrupt.

It is easy to maintain and change the voltage of AC electricity for transmission and distribution

AC system have:

Less cost

Less power loss

Less maintenance

The direct-current system generated and distributed electrical power at the samevoltage as used by the customer's lamps and motors. This required the use of large, costly distribution wires and forced generating plants to be at a close distance to the loads. With the development of a practical transformer, alternating-current power could be sent long distances over relatively small wires at a convenient high voltage, then reduced in voltage to be used by a customer. Alternating current generating stations could be larger, cheaper to operate, and the distribution wires were less expensive

AC transmission is more economic tan DC transmission. We can reduce the cable size and also can reduce losses while we transmit a signal in AC

THIS IS BECAUSE AC IS EASY TO CONTROL,i.e BY THE USE OF TRANSFORMER

AND THE LOSSES IN TERMS OF DISTANCE IS LESS SIGNIFICANT 

AGAIN AC TRANSFORMERS ARE READILY AVAILABLE UNLIKE DC TRANSFORMER.

DC IS MOST COSTLY TO CONTROL