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Minggu, 09 Desember 2012

Why when we turn off the televison the lamp still on?



Have you ever torn off one lamp in your house? What happend to other lights lamp? Is it turn off too?. The answer is no, the other lamp will not turn off too. Why it can be happend?, it is because our electricity in home using parallel circuit. To make you easier understand this concep, now i will give you a small experiment to proove that, check it out  :).

Required materials : 1. Two flashlight bulbs with sockects
                               2. Dry cell
                               3. Half a meter copper wire
                               4. Switch
                               5. Scissor

Step by step procedure :
1.    Cut the wire into five parts by scissor. Then strip about 1/2 inch (1.25 cm) of insulation from each end of the wires.
2.    Attach a wire to the positive side of the dry cell and connect the other end to the left side of a light bulb
3.    Attach another wire to the negative side of the dry cell and connect it to the switch
4.    Get another wire and conncet to the switch to the right side of the light bulb
5.     Add one more bulb to the setup by connect another wire to the left side of the first bulb and connecting the other end on the left side of the second bulb
6.    Connect another wire to the right side of the first bulb and connect it to the right side of the second bulb. Caution : Do not leave the wires on the screws for more than 5 to 6 seconds. The bare wire and lamp can get hot enough to burn you. Allow them to cool before touching them. The circuit  picture :

7.    See what happend when to the fiirst bulb when the second bulb added.

Result:
The adding of the second bulb is not affect to the brightness of the first bulb. The connection was not broken, the first buln is still on and light.

Why?
The electric current has more than one path to follow through the connected lamps in this experiment, so the circuit formed what is called a parallel circuit. The arrows in the electrical schematic in Figure 18.2 indicate the movement of the current (e') away from the negative terminal of the battery through the bulbs, then back to the positive terminal of the battery. At junction A (one of the screws on the side of lamp base 1), the current divides before moving through the lamps. Then the current recombines at junction B (one of the screws on the opposite side of lamp base 1) and returns to the positive terminal of the battery. The facts that the lamps are identical and glow with equal brightness show that the same amount of current reaches both lamps. This way, it is better than series circuit since the devices can be switched on and off separately without breaking any circuits and best circuit at home.



8 komentar:

Anonim mengatakan...

what if the lights in the house we use the composition of the series? What will happen?

melvika anggraini mengatakan...

Thank you gusma :)
if the circuit at home we use series circuit, it will very hard to us to do activyty, because when we urn off the televesion example, the lamp or refrigirator will off too, because they have one sources of voltage. And if it happend, it will broke the circuit, so i think impossible for us to use series circuit at home :)

Unknown mengatakan...

What factors led to the first light bulb still burning brightly in a parallel circuit?

melvika anggraini mengatakan...
Komentar ini telah dihapus oleh pengarang.
melvika anggraini mengatakan...

Thank you afni :)
That is because the second bulb get the same current from dry cell :)

Unknown mengatakan...

that's good melvika..
but I want to ask you,
what are the disadvantages to using a parallel circuit??.,.,

SABAR FISIKA mengatakan...

hy Melvika,,,,,,
btw
how about the capacitor,,,,
I think influence from the capacitor that is saving current...
so the lamp is oN..

please explain about your post<<
thanks>>

sudut pandang lia mengatakan...

Melvika,
if the parallel circuit applied in many homes, so, when and for what the series circuit has used?

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