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Current flow is from positive to negative. Use the left hand rule for finding the north and south poles. Grab the coil in your left hand, with your fingers wrapped around the coil in the direction of the current flow. Your thumb will then point toward the north pole of the coil.
Reverse the positive - negative connections to the coil and the north - south poles will change ends. The left hand rule will still be in effect as the current will now be flowing in the reverse direction as it was in the first connection.
What else can I help you with?
What are the factors determining the size and direction of a generated emf?
There are three factors for determining the size and direction of the emf generated from an AC generator. the strength of the magnetic field, the size of the field, and the speed of the rotation combine to determine this.
Why does the rotation of the motor reversed when change the polarity across the main winding coil?
When changing the auxilary face winding connection the current flow in the winding is changed so that the rotating emf direction is changed . Thats why the motor rotates in opposite direction.
Difference between back EMF and induced EMF?
An induced electromotive force (emf) is an induced voltage. Voltage (emf) causes current flow, and this induced voltage will cause a current that is called the induced current.We might also add that the induced current will cause a magnetic field to expand about the current path, and this field will "sweep" the conductor. The sweeping of the conductor by that expanding magnetic field will set up an emf that will oppose the emf that was creating it.CommentTechnically, there is no such thing as an 'induced current'. It is voltage that is induced. Any current flows as a result of that induced voltage being applied to a load. But that current is certainly NOT induced!
Why does the induced emf known as back emf?
In a dc motor the voltage generated in the armature acts against the supply voltage. The current is the voltage difference divided by the armature resistance. If the rotor is turned faster so that the back emf exceeds the supply voltage, the current goes the other way and the motor has become a generator.
Does motional emf call induced emf?
yes indused emf is also called motional emf. If an open coil is subjected to a variable magnetic field, at the ends of the coil a potential difference is induced which is called induced emf. If a coil is connected to an emf source and switched on, the rising current will produced an variable magnetic field which in turn produces an emf. It is called back emf.
Is emf a scalar or vector quantity?
Emf has direction within a current loop, though it is not scalar. It's a bit between though as direction should be otherwise accounted for when discussing induced Emf. Not quite either.
What are the factors that determines the size and direction of the generated emf?
The size of the generated electromotive force (emf) is determined by the rate at which the magnetic field changes within a circuit, and the number of turns in the coil. The direction of the emf is determined by Lenz's law, which states that the induced current will flow in a direction that opposes the change in magnetic field that produced it.
What is the statment of lenz law?
The direction of an induced emf or current is such that the magnetic field created by the induced current opposes the change in magnetic flux that created the current.
What does the lenz law state?
The direction of an induced emf or current is such that the magnetic field created by the induced current opposes the change in magnetic flux that created the current.
Does current depends on its resistance?
The current flow in an electrical circuit depends on the applied electromotive force (EMF, measured in volts), and the total resistance along the entire circuit. Rising EMF or dropping resistance cause increased current flow
Does the direction of emf provided by the battery depend on the direction of the current flow through the battery?
Yes, the direction of the electromotive force (emf) provided by the battery does depend on the direction of the current flow through the battery. The emf is always in the direction opposite to the flow of electrons within the battery, which is also the direction of conventional current flow. This is based on the concept of the conservation of energy and the work done by the battery to move charges through the circuit.
What is the emf induced at zero field current.and what does it signify?
EMF is the voltage across a coil (or motor) due to changes in the magnetic field. If you change the current the coil will generate a voltage (in the opposite direction of the current). So it is not the field but the change that matters.
What are the factors determining the size and direction of a generated emf?
There are three factors for determining the size and direction of the emf generated from an AC generator. the strength of the magnetic field, the size of the field, and the speed of the rotation combine to determine this.
Why does the rotation of the motor reversed when change the polarity across the main winding coil?
When changing the auxilary face winding connection the current flow in the winding is changed so that the rotating emf direction is changed . Thats why the motor rotates in opposite direction.
The direction of a magnetic field produced by an electric current depends on the direction of the what?
The direction of a magnetic field produced by an electric current depends on the direction of the current flow. The magnetic field will form circular loops around the current-carrying wire, following the right-hand rule.
How does moving the magnet towards or away from the coil affect the direction of the current?
Moving the magnet towards the coil induces a current in one direction, while moving it away induces a current in the opposite direction. This is due to Faraday's law of electromagnetic induction, which states that a changing magnetic field induces an electromotive force (EMF) that leads to the current flow.
Is emf current greater than current?
EMF is electromotive force. It is another name for voltage. Voltage is electric potential in joules per coulomb. Current is electric flow, in amperes. Amperes are coulombs per second. Voltage and current are not the same thing, and "emf current", or "voltage current" does not make sense.
