and, why the effective resistance for parallel resistors is always smaller than any of the individual resistances?
2006-09-01 03:44:09 · 7 answers · asked by shakti 1 in Science & Mathematics ➔ Physics
In a series circuit, the current has no choice but to travel through every resistor in the circuit, so the effect is cumulative.
In parallel, the current gets divided amongst the resistors, so that the overall resistive effect is lessened.
2006-09-01 03:50:37 · answer #1 · answered by Professor 3 · 2⤊ 0⤋
current flows when u apply a potential difference.
In case of a series of resistors, current has only one path to take and hence, it has to pass through all the resistors. Hence, the net resistive effect (effective resistance) the sum of all the resistors (which will obviously be greater than any indivudual resistor)
In case of parellel resistors, each resistor act as if the others does not exist. Hence, overall current flow is the sum of currents flowing thorugh indivudual resistors.
ie, more current across same voltage, which means less resistance.
2006-09-01 04:38:30 · answer #2 · answered by MobiGuru 2 · 0⤊ 0⤋
Because if you are making a resistor out of the same stuff, the longer it is, the higher the resistance, while the thicker across it is, the lower the resistance. Two identical resistors in series are equivalent to one made of the same stuff which is twice as long. Two identical resistors in parallel are equivalent to one made of the same stuff which has twice the cross section.
2006-09-01 03:52:49 · answer #3 · answered by Benjamin N 4 · 0⤊ 0⤋
Its due to the fact that a resistor opposes current, or drops voltage. If you run 12 volts across a 100 ohm resistor you will get "x" amount of current. If you lower the resistance, the current will increase. Think of the current path as a hose with water in it. If something in the line opposes the flow, there will be less water.
2006-09-01 03:53:40 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Well, lets see...
If you have two bags of ice, put them one after another (series), and you shoot a bullet into one, and it travels through the other, you have a lot of resistance on the bullet, and thats like ions, trying to travel through the water, it slows it down.
Now, if you take both bags of ice, and put them side by side,(parallel), and shoot a bullet into one, and not the other, then it has less resistance to travel., as its only getting half the resistance.
Simplistic way of putting it, but it works for me.
I wish you well..
Jesse
2006-09-01 03:51:25 · answer #5 · answered by x 7 · 0⤊ 0⤋
for resistances with the same value (example Ra=Rb):
1.the effective resistance increases as you add them up instead of individual resistance.
2. referring to the equation of total resistance in parallel
= (Ra+Rb)/RaRb,thus the value decreases (which in this case, is half of the initial value) compared to individual resistance
2006-09-01 03:53:19 · answer #6 · answered by ^_^ 1 · 0⤊ 0⤋
The more cashier the lesser the queue and you can go home earlier.Hope you got it.
Have a nice day.
2006-09-01 06:02:08 · answer #7 · answered by dwarf 3 · 0⤊ 0⤋