Talking about the home appliances and electronics, if it is single phase that we are using in houses and currents get to zero every half cycle, how do the home appliances (using AC) and electronics (using AC as rectified to DC) continuously function (inspite of periodically recieving 0 current)?
how do the home appliances (using AC) and electronics (using AC as rectified to DC) continuously function (inspite of periodically recieving 0 current)?
A full wave rectifier and reservoir (smoothing) capacitor are used to "hold-up" the voltage during the time that the AC is close to zero volts: -
It acts like a water tank - if the main water feed into the home gets shut down for a period of time, the reserve water tank will keep the home supplied in water until the main water feed flows again.
how do the home appliances (using AC) ...
Because motors have inertia:
When you spin a motor using single-phase AC, the torque goes to zero when current goes to zero. The actual torque being transmitted from the windings to the armature is roughly sinusoidal at twice the line frequency (so, 120Hz for a 60Hz line frequency). The motor spins because the average torque is in the desired direction, but it is kept spinning through the current zeros by inertia.
and heaters have heat capacity:
The situation is the same for a heater -- the actual heat being dissipated in the heater is AC at twice the line frequency, plus some average heat. (It goes as \$(\cos \omega t)^2\$). Heaters generally have long time constants, so the temperature is averaged out.
and eyeballs have persistence of vision:
Similar to the above, it take some time for your visual receptors to respond to changes in the light striking them. Most lighting (even incandescents, to some extent) flash on and off, or at least vary in intensity, at twice the line rate. You perceive the light as steady because the light-sensitive cells in your retina time-average the light coming into them.
The home appliances and other devices that do not use rectifiers use thermal and mechanical mass to smooth operation under pulsating power. The element of an incandescent light bulb does not cool very much when the power drops to zero for a small fraction of a second, so we don't notice the lights flicker. Single phase motors vibrate and make more noise than that three-phase motors, but inertia keep the speed relatively constant. Some single-phase motor have capacitors that are continuously connected, that smooths the power somewhat. Other motors get some smoothing from the difference in resistance and inductance in two current paths inside the motor. Loops of wire, called pole shades, around a portion of the magnetic core also help to reduce vibration and smooth torque in motors and reduce vibration in electro-magnets.