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In metal conductors, current is a flow of electrons. As electrons are negatively charged, they are repulsed by an external negative charge and attracted towards an external positive charge. In other words, electrons travel from negative to positive.
Before the structure of an atom was understood, scientists such as Benjamin Franklin believed that current was a flow of some type of mysterious fluid, which flowed from an area of high pressure, to an area of low pressure. High pressure was considered to be positive, while low pressure was considered to be negative. For this reason, it was believed that current flowed from positive to negative.
To differentiate between these two theories on current flow, we call the modern theory 'electron flow' and we call the older theory 'conventional flow' (or 'Franklinian flow').
Conventional flow was established for such a long time, that a great many (in fact, probably most!) textbooks still continue to use it, even though they know the direction is the wrong way around! In my view, this is unfortunate as it can lead to confusion where there need not be any. Nevertheless, we have to live with it!
In practise, it doesn't really matter which one is used, just so long as it is used consistently. As many of the 'laws' relating to the polarity of electromagnets depend on current direction, when studying magnetism it's very important to determine whether 'electron flow' or 'conventional flow' is being used. For example, Fleming's Left-Hand Rule for conventional flow becomes Fleming's Right-Hand Rule for electron flow!
What else can I help you with?
Total opposition to current flow in an AC circuit?
I oppose alternating current. Direct is the only way for me. That is 1 in opposition.
What is electical circuits?
It is a way in which electrons from a voltage or current source stream. Electric current stream in a shut way is called an electric circuit. The point where those electrons enter an electrical circuit is known as the source of electrons.
What is phase angle in ac?
It's the amount by which voltage leads current (or vice versa) in the AC circuit. By convention, the phase angle is positive in inductive circuits (where voltage leads current) and negative in capacitive circuits (where current leads voltage).AnswerUnfortunately, the original answer has things the wrong way around. By definition, phase angle is the angle by which the current leads or lags the supply voltage (not the other way around). Therefore, the phase angle is considered negative (current lagging) for an inductive circuit, and positive (current leading) for a capacitive circuit. This is because, for a phasor diagram, counterclockwise is the positive direction, whereas counterclockwise the the negative direction.
What happens when a light bulb is unscrewed in a series circuit?
All other light bulbs will turn off due to the series circuit being broken. The electrons cannot travel all the way through, hence the current will also not flow in the circuit, switching off all the other bulbs too.CommentIt's worth pointing out that the full supply voltage will then appear across the lamp holder -so take care!
What effect will occur if the intermediate switch is replaced by a double pole switch?
The circuit will not work. In a three way lighting circuit system the middle switch needs to cross the traveller wires to be effective. A double pole switch in the circuit will just open both traveller wires and disrupt the current flow in both wires. No current flow, no lights.
How can a fuse stop the current flowing if the currents to big?
it gets broken A fuse is specifically designed so that when the current exceeds its specified rating, the fuse itself fails in some way (usually, part of it melts or burns out). When the fuse "blows", the circuit is cut open, so current can no longer flow.
How much current flows through circuit breaker trip coil?
The trip coil has the whole circuit load amperage flowing through it. Thepurpose of the breaker is to only allow current up to its trip point. That is the only way that the breaker can sense if the current is within the limit rating. If the circuit load amperage becomes greater that the breaker rating it will trip. The trip coil that you refer to is a magnetic trip which senses the magnetic field that surrounds the wire. Breakers also have a thermal trip which senses a heat build up on the current flowing through it. If the breaker is in a high ambient temperature it will lower the rating on the breaker.
What is a currnet?
Direct current is a flow of electricity which only goes one way. Batteries, for example, produce direct current, so the current must flow all the way through a circuit and back into the battery to work. Alternating current is what comes out of a wall outlet, and it alternates in both directions, with current flowing in and out of the outlet.
Normally open devices are wired how?
The wiring of a N.O. or N.C. device is dependant on the function of what is to be done by the circuit it is in. The ambiguity of the question should be more defined as to what the device is and the operation it is supposed to preform in the circuit.
What is wrong with the statement Voltage flows through a circuit?
Voltage is the force that causes current to flow through a circuit. In a similar way it isn't pressure that flows through a pipe - it is the fluid flowing through a pipe due to a difference in pressure at the entry and exit of the pipe that causes the fluid to flow through, no pressure flowing through a pipe.
What is series of a circuit?
is a way two path in current
How do you convert a volt into a watt?
Volts are an electrical measure of potential difference and Watts are a measure of power. The high school physics way of calculating the power (P) in watts, would be to multiply the given current (I) by the voltage (v). P = V * I From Ohms Law we know that V = I * R, where R is the resistance of the electrical circuit given in Ohms, so we could also state that P = (I * R) * I = I2 * R So you have two equations there that should be useful.
Is the current in a series circuit high all the way round?
That depends on what you call "high".Whether or not you consider it high, the current is the same all the way around a series circuit.
What does kirchoff's law state?
Kirchhoffs Laws are statements about circuits. There are two laws ; 1) The total current entering any point in a closed circuit equals the total current leaving that point. 2) The sum of the voltage changes around any closed path is zero. These "Laws" are a consequence of the more fundamental laws of conservation of charge and conservation of energy.
What is a parralell curcuit?
• In a parallel circuit, there are junctions in the circuit so the current can flow around the circuit in more than one way. • In a series circuit the current decreases as more bulbs are added. •In a parallel circuit, as more bulbs are added, the current increases. • This is because bulbs added in parallel offer less resistance
You are monitoring electric current in a circuit. you notice the voltage increasing this mean's that?
Ohm's Law states that the current (I) flowing in a circuit is directly proportional to the applied voltage (E) and inversely proportional to the circuit's resistance (R).I = E/RAnother way of stating Ohm's Law is that the applied voltage (E) is directly proportional to both the current (I) and the resistance (R).E = IxR.So, if the voltage (E) is increasing, then either:if you know the resistance (R) is staying constant then the current (I) must be increasing - which you would see because you are monitoring it! or, if the current (which you are monitoring) is actually staying constant, then, for the voltage to be able to increase:the circuit's resistance must be increasing orthe increasing voltage could be caused by a combination of both increasing current and increasing resistance!
Current electricity and words that describe it?
current electricity is energy that never stops and is what keeps our computer running every day and night.Imagine the current adventurers and the circuit is a tunnel.The advetures moving in the tunnel MOST of them will choose the fast way some will choose the long way.
