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A 120 ohm resistor a 60 ohm resistor and a 40 ohm resistor are connected in parallel to a 120 volt power source What is the effective resistance of the three esistors?
Wiki User
∙ 14y ago
The effective resistance of three resistors, 120 ohm, 60 ohm, and 40 ohm, in parallel is 20 ohms.
RP = 1 / sum (1 / RN)
RP = 1 / (1 / 120 + 1 / 60 + 1 / 40)
RP = 20
The voltage applied, 120V, does not change the outcome. The power, however, of the three resistors is 120W, 240W, and 360W respectively. This is a lot of power, so please do not attempt to do it for real.
Wiki User
∙ 14y ago
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∙ 11y ago2.0 or two
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To connect a pair of resistors so that their equivalent resistance is greater than the resistance of either one should you connect them in series or in parallel?
When many resistances are connected in series, the equivalent resistance is greater than the greatest single resistance. When many resistances are connected in parallel, the equivalent resistance is less than the smallest single resistance.
How to measure resistance of series combination?
When connected in series, the overall effective resistance of a bunch of individual resistors is the sum of the individual resistances. It's always more than the resistance of any individual. When connected in parallel, the reciprocal of the overall resistance of a bunch of individual resistors is the sum of the reciprocals of the individual resistances. It's always less than the resistance of any individual. When two resistors are connected in parallel, the overall effective resistance of the pair is (the product of the two individual resistances) divided by (the sum of the two individual resistances). It's always less than the smaller individual resistance.
How are parallel resistors connected?
If you need a resistor of a certain value, and you have no resistors with small enough values,you can create the one you need by connecting several of those you have in parallel.The effective net resistance of resistors in parallel is always less than the smallest individual.And the more resistors you add in parallel, the smaller the net effective resistance becomes.
Why is resistance less when resistors are join in parallel?
What do you mean? In a parallel circuit, the combined (or effective) resistance is less than any individual resistance.
What is a resistance network?
A resistance 'network' consists of a number of resistors connected together in series, or in parallel, or in series-parallel, or as a complex circuit. A 'complex' circuit is one that is not series, parallel, or series-parallel.
How is resistivity connected to resistance?
Resistance is connected in parallel with voltmeter or say, voltmeter is connected in parallel with resistance.
What happen when ammeter connected in parallel?
an ideal ammeter has zero or negligible resistance when this is connected in series no effective resistance would be added in the circuit so that the value of curret that we get is exactly of the circuit only. but when the ammeter is connected in parllel as it has zero resistance , the resistor to which it is connected in parllel gets shorted and due to his the effective resistance of the circuit is changed and so the effective current ... due to this the w=value measured by the ammeter would be different (incresed due to dec. in effective resistance)
Is it possible to connect a group of resistors of value R in such a way that the equivalent resistance is less than R?
Yes. When resistors are connected in "parallel" (all the left ends connected together and all the right ends connected together) the effective resistance is always less then the smallest resistor in the group. For example If you connected a 2 ohm in parallel with a 4 ohm the effective resistance is 1.33 ohm. To your question; if you connect N equal resistors R in parallel the effective resistance would be R/N . The formula for calculating effective resistance R of a group R1, R2, R3, ... in parallel is: 1/R = 1/R1 + 1/R2 + 1/R3 + .... Note; write the right side as a single fraction by getting a common denomenator then invert to get R.
A 120 ohm resistor a 60 ohm resistor and a 40 ohm resistor are connected in parallel to a 120 volt power source. What is the effective resistance of the three resistors?
The effective resistance of those three resistors in parallel is 20 ohms. And it makes no difference what the power source is, or whether they're even connected to a power source at all. As soon as those three resistors are in parallel, their effective resistance is 20 ohms immediately, even if they're still in the drawer.
If additional resistance is connected in parallel with a circuit the supply voltage will decrease?
If additional resistance is connected in parallel with a circuit the supply voltage will decrease?
What happens to supply voltage if additional resistance is connected in parallel circuit?
No change in supply voltage as additional resistance is connected in parallel circuit.
What is the equivalent resistance of the parallel circuit you have connected?
In principle, it is infinite. I have not connected a parallel circuit in ages.
When two resister of 1000 ohms are connected in parallel their effective resistance will be?
500 ohms. RP = 1 / summation (1 / RI)
To connect a pair of resistors so that their equivalent resistance is greater than the resistance of either one should you connect them in series or in parallel?
When many resistances are connected in series, the equivalent resistance is greater than the greatest single resistance. When many resistances are connected in parallel, the equivalent resistance is less than the smallest single resistance.
How to measure resistance of series combination?
When connected in series, the overall effective resistance of a bunch of individual resistors is the sum of the individual resistances. It's always more than the resistance of any individual. When connected in parallel, the reciprocal of the overall resistance of a bunch of individual resistors is the sum of the reciprocals of the individual resistances. It's always less than the resistance of any individual. When two resistors are connected in parallel, the overall effective resistance of the pair is (the product of the two individual resistances) divided by (the sum of the two individual resistances). It's always less than the smaller individual resistance.
How many 40 Ω resistors connected in parallel are required to carry 1.5 A on a 12.0 V line?
The required resistance is 12/1.5 = 8Ω.Five 40Ω resistors in parallel have an effective resistance of 8Ω.
What is the resistance of 70ohms and 30ohms connected in parallel?
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