What are two things required to have a current in a circuit?
2006-07-12 20:48:23 · 11 answers · asked by lady_bugs_2000 2 in Science & Mathematics ➔ Physics
You need a potential difference between two points in the circuit. (I assume that when you say a circuit that you mean a closed circuit of conducting wire). Then current will flow.
2006-07-12 20:53:25 · answer #1 · answered by blind_chameleon 5 · 0⤊ 0⤋
Well, once you have a complete circuit, you can ask this question either way around and it is very important to understand why.
You could apply a potential difference - this means you make the electrons at one end of the circuit have a higher energy than the other. Electrons will then flow from high energy to low energy as a current. This is how you think of things when you use a power source that applies a constant voltage that does not vary with current - the mains electric and batteries behave more or less like this.
But it is eqaully valid to say that you drive electrons round the circuit and the potential difference arises because they lose energy as they pass through it. This is how to think of things when the power source delivers a constant current which does not vary with the voltage across the circuit (i.e. it would not change if you added the odd resistor). Photo cells behave like this.
2006-07-13 04:10:46 · answer #2 · answered by Epidavros 4 · 0⤊ 0⤋
Current is the rate of flow of charges thorough a medium.
Charges flow from high potential to low potential.
If these two are there then charge will flow.
But we can simplify it by saying that there must be a potential difference between two points.
Thus for a current, there must be two points; one point must be in high potential and the other must be at a low potential; the two points must have free ( free to flow) charges in between them.
2006-07-13 04:23:46 · answer #3 · answered by Pearlsawme 7 · 0⤊ 0⤋
hello friend,
your question is very fine! and intellectual too, the answer is very simple that is +ion and -ion that means north pole and south pole the + ion is a high density energy and the - ion is a low density energy when it rotates in a particular direction and correct speed the current is created in the circuit. I think i am correct. If i am wrong i am sorry if you come to know the answer please share with me.
2006-07-13 04:12:46 · answer #4 · answered by kuppu_n 1 · 0⤊ 0⤋
Voltage potential or pressure & circuit resistance.
2006-07-13 04:04:10 · answer #5 · answered by FILO 6 · 0⤊ 0⤋
Voltage and resistance
2006-07-13 05:13:45 · answer #6 · answered by paulofhouston 6 · 0⤊ 0⤋
potential difference: actually address "two things"
2006-07-13 03:52:23 · answer #7 · answered by Kreep 3 · 0⤊ 0⤋
a "complete" ciruit, and a voltage source ( for currect)
2006-07-13 03:54:09 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Some kind of stimulus, and some kind of medium.
2006-07-13 03:52:20 · answer #9 · answered by smokingun 4 · 0⤊ 0⤋
voltage (emf) and continuity
2006-07-13 03:53:46 · answer #10 · answered by mickyyyyy 3 · 0⤊ 0⤋