Suppose we have two pole maganit North and pole and one single loop coil with two wire end A and B , both are moving through some mechanical force and cutting the magnatic lines of field between the two poles. my question is both wires are moving in opposite direction so both producing emf in opposite direction.. How current flow from one side of the coil A to second side of the coil B.. i am confuse between opposite polarity or higher potential.. i am attaching one picture for reference ....
the current in each wire is in opposite direction - but each piece of wire forms opposite side of circle (the coil) - so the currents add in either a clockwise or anticlockwise direction.
I forgot to mention, your drawing, in a dc generator, your left field pole would be N, your right pole would be S, your armature would also develop N & S poles, rotation would create attraction or repulsion, likes repel, unlikes attract...........
when you magnetic field is established, picture stright lines between your field poles these are the magnetic lines
these are the lines your armature conductors are cutting
draw a black dot at 0 degrees draw a black dot at 90 degrees draw a black dot at 180 degrees draw a black dot at 270 degrees draw a black dot at 360 degrees
Part of the confusion comes from your drawing is that it over simplifies the idea. For that drawing to work properly the meter would have to spin with the A and B winding with each meter lead staying in constant contact with it's AB leg. It would produce AC OR the wire loop would alternate contact with the meter leads as it spins and would produce DC. In the DC case the switching mechanism would be called a commutator. To visualize the alternator just think of the N and S poles spinning instead of the AB loop. The needle on the meter would be alternating from left to right indicating positive and negative flow. Even though the reletive rotation of the AB loop and field has not changed the North South direction flux is reversing every 180 degrees.
The direction of electron flow is reversed if either the polarity of the flux or the direction of conductor movement is reversed
The rule of thumb is called the Right hand rule of generators and there is a corresponding Left hand rule of motors and can be fully explored here: http://en.wikipedia.org/wiki/Fleming's_left_hand_rule_for_motors
This may not be where the "rule of thumb" saying came from but it cetainly reinforced it's use.
Dear Sir, My question is still not clear. Two wires A,B having induced voltages in opposite polarities but have same level of emf . because both have same length, velocity and magnatic field so if both have same level of emf then how potential diffrence create across the wire terminals A, B which cause the flow of current???
I am thinking you beleive the current flow in the A and B conductor is flowing in opposite directions. It is not, because the A leg is passing through the flux in one direction, let us presume up, and the B leg is passing through the flux in the opposite direction, down. You could place a + and - on each end of the AB legs. A will have the + closest to you and the B will have the - closest to you. It doesnt matter which way you do it at first, because depending on the moment you observe the rotating position, in 180 degrees it will reverse in BOTH legs. Since the AB legs are connected at the far end the current flow is in the same direction in the conductor. So the flow is + to - in A and + to - in B. The - of the A is connected to the + of the B just like you would connect batteries in series.
If this doesnt help I have misunderstood your question.
The discussion addresses the confusion about current flow and potential difference in a single loop AC generator with two wires (A and B) moving through opposite magnetic flux directions. Although each wire induces an electromotive force (emf) in opposite polarity due to their opposite motion through the magnetic field, the coil forms a closed loop where the currents in each wire add up in a consistent direction around the loop, either clockwise or anticlockwise. The potential difference across terminals A and B arises because the two sides of the coil experience emf of the same magnitude but opposite polarity, creating a voltage difference that drives current flow. The magnetic field lines between the North and South poles are cut by the armature conductors, inducing voltage that varies sinusoidally with the conductor's position relative to the poles (0°, 90°, 180°, 270°, 360°). The current direction reverses every half rotation (180°), consistent with AC generation principles. The right-hand rule for generators explains the relationship between conductor motion, magnetic field direction, and induced current. The coil ends are connected such that the current flows continuously in one direction around the loop, analogous to series-connected batteries with opposite polarities. The discussion also distinguishes between AC and DC generators, noting that a commutator is required to produce DC by switching contacts as the coil rotates. Summary generated by the language model.
