what is the main difference between direct current and alternate current?

Answer 1

The ability to transport DC over longer distance is less effective.

That's why Edison lost out to Westinghouse with supplying electricity to municipalities.

Answer 2

In DC, the negative terminal remains negative throughout and the positive terminal remains positive throughout. So, if a person gets a shock from DC current, he will be glued to the electrical appliance as the current moves in the same direction. In AC, the current moves in alternating directions since once the positive terminal is positive and then, within a very short span of a second, it becomes negative. Since the current moves in alternating directions, the person is thrown far away instead of being attached to the appliance. The person is thrown far away when he comes in contact with AC, so the person does not receive a major shock.

Answer 3

Direct current is nothing more than a difference of voltage potential between to places. The difference can be anything. For example, if you have -2 volts on one post and +15 volts on another and you connect them with a wire, you have an immediate difference of 17 volts DC producing current along the wire until the difference evens out to zero, and current will stop.

AC voltage requires fluxuation in voltage potentials, and it has to be stable to be meaningful or useful. We use generators and alternators to produce artificial AC, and what we usually end up with is a nice, even variation ("alternating") between equal opposites, such as between +8 and -8 volts at even intervals. Together, they're called 8 volts AC.

Naturally occuring AC includes sound waves and light waves which can be measured both in frequency and voltage (voltage becomes either a measure of volume or brightness).

Answer 4

(m)

Electricity flows in two ways; either in alternating current or AC and in direct current or DC. The word electricity comes from the fact that current is nothing more than moving electrons along a conductor, like a wire, that have been harnessed for energy. Therefore, the difference between AC and DC has to do with the direction in which the electrons flow. In DC, the electrons flow steadily in a single direction, or "forward." In AC, electrons keep switching directions, sometimes going "forwards" and then going "backwards." The power that comes from our wall outlets is AC, the more common, efficient kind.

Electricity is a very different energy source than heat or light. In nature, electricity only rarely occurs, in some animals, or with lightning. In the search to create electrical energy, scientists discovered that electrical and magnetic fields are related. A magnetic field near a wire causes electrons to flow in a single direction along the wire, because they are repelled by the negative side of a magnet and attracted toward the positive side. Thus, DC power from a battery was born, primarily attributed to Thomas Edison's work and promotion.

Another scientist, Nikola Tesla, preferred AC because it travels farther without losing energy and could transfer different amounts of power. Instead of applying the magnetism along the wire steadily, he used a magnet that was rotating. When the magnet was oriented in one direction, the electrons flowed towards the positive, but when the magnet's orientation was flipped, the electrons turned as well. AC generators gradually replaced Edison's DC battery system because AC is safer to transfer over the longer city distances and can provide more power.

Another difference between AC and DC involves the amount of energy it can carry. Each battery is designed to produce only one voltage, and that voltage of DC cannot travel very far until it begins to lose energy. But AC's voltage from a generator, in a power plant, can be bumped up or down in strength by another mechanism called a transformer. Transformers are located on the electrical pole on the street, not at the power plant. They change very high voltage into a lower voltage appropriate for your home appliances, like lamps and refrigerators. AC can even be changed to DC by an adaptor that you might use to power the battery on your laptop.

Answer 5

DC or direct current is always positive and negative. Alternating current is alternating between positive and negative. One wire on AC will be positive, then negative and then possitive again, and this happen 50 - 60 times a second, depending on the source. The other wire does the same thing but is always opposite the first wire. (2 phase source)

Answer 6

Direct current (DC or "continuous current") is considered as the constant flow of electrons in the single direction from low to high potential. This is typically in a conductor such as a wire, but can also be through semiconductors, insulators, or even through a vacuum as in electron or ion beams. In direct current, the electric charges flow in the same direction, distinguishing it from alternating current (AC). A term formerly used for direct current was Galvanic current.


Types of direct currentLong after the usage of this term had been established, physicists realized that electrons actually flow to a negative potential (pole) and so-called "holes" flow to the opposite one. However, the established usage of the term prevailed.




An alternating current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant. The usual waveform of an AC power circuit is a sine wave, as this results in the most efficient transmission of energy. However in certain applications different waveforms are used, such as triangular or square waves.

Used generically, AC refers to the form in which electricity is delivered to businesses and residences. However, audio and radio signals carried on electrical wire are also examples of alternating current. In these applications, an important goal is often the recovery of information encoded (or modulated) onto the AC signal.

Answer 7

D.C. travels through a circuit in one direction only, A.C. changes (alternates) it's direction 50/60 times a second.Without A.C., power transmission as we know it would not be possible.

Answer 8

DC current doesnt change direction

AC current changes direction