alleryStart learning →Why is AC rather than DC used in most large-scale power distribution systems?
AAC currents are smaller at equal power
BAC lines have lower resistance than DC
CAC voltages are easier to raise and lower
DAC generators cost less than DC ones
Answer & Solution
Correct answer: C. AC voltages are easier to raise and lower
1. Long-distance transmission is cheap only if the voltage is very high, because the current is then small.
2. But the voltage delivered to a user has to be brought back down for safety.
3. So the system needs voltage to be changed twice, up at the plant and down at the point of use.
4. Changing an AC voltage is far easier than changing a DC one, which decides the choice.
5. A line's resistance is a property of its metal and geometry, so it does not depend on whether the current alternates.
_Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section Why Use AC for Power Distribution?_
Keep practising Electric Current, Resistance, and Ohm's Law
Browse all Electric Current, Resistance, and Ohm's Law questions for B.Tech EEE, or explore more Electrical Engineering topics.
Related questions
The T wave of an electrocardiogram is generated by which event?The QRS complex of an electrocardiogram is generated by which event?In a three-electrode electrocardiogram, the lead II potential is measured between which twMultiple sclerosis arises through which mechanism?Why is no cell energy spent in the myelinated stretches of an axon?Myelin is an insulator. What does that insulation achieve for an axon?What name is given to the unmyelinated gaps that separate the myelin sheaths along an axonCompared with an unmyelinated one, how does a myelinated axon carry a nerve impulse?