How do ac and DC voltages work?

Answer 1

the currents move back and forth ( alternating current) when something is plugged into a socket, the ac voltage (120 v) is moved to the device.

then there is dc voltage, dc voltage works with electricity flowing straight to a device, it does not alternate. just as a battery hooked up to a wire, connected to a switch, connected to a light, connected to the battery again.

ac could connect to the light from the switch , from the battery.

Answer 2

Voltage means potential difference. When at the electrode negative charges present more than positive charges and on the another electrode positive charges present more than negative charges then a potential difference occurs between these electrodes. Here negative electrode is anode and positive electrode is cathode.

Due to potential difference electrodes electrons flows from anode(-) to cathode(+). An energy flows in opposite direction to the flow of electrons that is current.

In alternating current (ac); its voltages magnitude is starts from zero, then reach to positive maximum, then decays to zero, then reach negative potential and then finally towards zero. This process of one cycle is make frequency of 1 hz. So as the current follows the voltages path and its waveform can be represented sinusoidally. But it is in the case of resistor load. In inductive load; current lags the voltages. In capacitive load; current leads the voltages.

In direct current (dc); its voltages magnitude does not changes its phase so its frequency is zero. As the current follows the voltage path; its waveform is straight line in resistive load.

Capacitor and inductor are storing elements. Capacitor stores the energy in the form of charges and makes a voltages across its terminals so its opposes the change in voltages. So current leads in case of capacitor. Inductor stores the energy in the form of magnetic field which opposes the changes in current. Thus current lags in case of inductor.

Answer 3

In electricity, alternating current (AC) occurs when charge carriers in a conductor or semiconductor periodically reverse their direction of movement. Household utility current in most countries is AC with a frequency of 60 hertz (60 complete cycles per second), although in some countries it is 50 Hz. The radio-frequency (RF) current in antennas and transmission lines is another example of AC.

An AC waveform can be sinusoidal, square, or sawtooth-shaped. Some AC waveforms are irregular or complicated. An example of sine-wave AC is common household utility current (in the ideal case). Square or sawtooth waves are produced by certain types of electronic oscillators, and by a low-end uninterruptible power supply (UPS) when it is operating from its battery. Irregular AC waves are produced by audio amplifiers that deal with analog voice signals and/or music.

The voltage of an AC power source can be easily changed by means of a power transformer. This allows the voltage to be stepped up (increased) for transmission and distribution. High-voltage transmission is more efficient than low-voltage transmission over long distances, because the loss caused by conductor resistance decreases as the voltage increases.

The voltage of an AC power source changes from instant to instant in time. The effective voltage of an AC utility power source is usually considered to be the DC voltage that would produce the same power dissipation as heat assuming a pure resistance. The effective voltage for a sine wave is not the same as the peak voltage. To obtain effective voltage from peak voltage, multiply by 0.707. To obtain peak voltage from effective voltage, multiply by 1.414. For example, if an AC power source has an effective voltage of 117 V, typical of a household in the United States, the peak voltage is 165 V.

Answer 4

The basic idea of AC (alternating current) is that the voltage, and the current, continuously changes its direction; usually forming a sine curve if it is graphed. Commercial electricity, as the one you get in your home's power outlet, usually has a frequency of 50 or 60 hertz (cycles per second), depending on the region.

Answer 5

See this link:

http://www.ehow.com/how-does_4568640_ac-electricity-work.html