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When a direct current (DC) flows through a conductor, it generates a magnetic field around the conductor. This phenomenon is described by Ampere's law, which states that a magnetic field is produced around a current-carrying conductor. The strength of the magnetic field is directly proportional to the current flowing through the conductor.
What else can I help you with?
In an electromagnet as the electric current changes what happens to the magnetic field?
As the electric current changes in an electromagnet, the strength of the magnetic field also changes. An increase in current strength leads to a stronger magnetic field, while a decrease in current strength results in a weaker magnetic field. This ability to control the magnetic field strength makes electromagnets versatile in various applications.
Why a current wire deflects a magnetic needle placed near it?
A current wire deflects a magnetic needle placed near it because the current wire is creating an electric field. If the current is supplied from an AC (alternating current source as opposed to DC which is direct current- AC would be from a wall socket, DC from a battery), then the current is constantly changing, so the electric field is constantly changing. A changing electric field results in a magnetic field perpendicular (90 degrees) to it. It is actually the magnetic field that is changing the needle direction, because that needle is trying to follow the magnetic field lines (similar to those that you see when you put iron filing near a magnet).
Why current is supplied to DC motor?
What supplies a dc motor is not current, but voltage. Current is what flows in the circuit formed by the dc motor and for the charge. That current varies according to the resistance of the circuit.
How do DC motors produce torque?
DC motors produce torque through the interaction between the magnetic field generated by the electromagnets in the stator and the magnetic field of the permanent magnets in the rotor. When current flows through the coils, it creates a magnetic field that interacts with the rotor's field, creating a force that rotates the rotor and produces torque.
Why a transformer only work with alternating currents?
The iron core of a transformer holds a magnetic field when energized by the primary windings that conduct current. It is the building up and collapse of the magnetic field that induces current in the secondary windings. Direct current has no build up or decay of magnetic field (except when turned on and shut off) so no current is induced in the secondary windings.
What is the effect of field current on dc motor?
The field current of a dc motor provides the magnetic field that allows the motor to develop a torque when current flows through the armature..
Why is dc current used in the excitation of generator?
The field current is used for the excitation of generators.AnswerYou use DC current, because you want the resulting magnetic field to be constant. If you used AC, the resulting magnetic field would vary in both strength and direction.
Is electromagnetism is possible with AC?
AC current creates an alternating magnetic field, consistent with the alternating voltage. The only way I know of using AC current to create a constant magnetic field is to rectify the AC into DC and then use that DC to create the magnetic field.
Can a dc electric field produce magnetic field?
Yes. A steady current will produce a magnetic field, B= uI/r
In an electromagnet as the electric current changes what happens to the magnetic field?
As the electric current changes in an electromagnet, the strength of the magnetic field also changes. An increase in current strength leads to a stronger magnetic field, while a decrease in current strength results in a weaker magnetic field. This ability to control the magnetic field strength makes electromagnets versatile in various applications.
Can DC be used for transformer?
Basis of transformer is change in current. Whenever current flows it causes magnetic field. Current flow in primary coil causes magnetic field around secondary. Since current is changing as in the case of AC, magnetic filed also changes. As per Faraday's law change in magnetic field causes induced voltage at secondary coil. In case of DC there wont be any change in current, thus no change in magnetic field leading to no induced voltage.
Why doesn't a transformer work only on a DC supplyand not in ac supply?
A transformer doesn' t work with DC current because voltage is induced in the output winding of the transformer when a magnetic field passes through the coils of this winding. This happens with AC current because the magnetic field is continually expanding and contracting. With a DC current the magnetic field is unchanging other than when you first turn it on. Since the magnetic field is not moving it is not moving through the windings and no voltage is produced.
Armature reaction in a DC generator?
ARMATURE REACTION in DC MachineAll current-carrying conductors produce magnetic fields. The magnetic field produced by current in the armature of a dc generator affects the flux pattern and distorts the main field. This distortion causes a shift in the neutral plane, which affects commutation. This change in the neutral plane and the reaction of the magnetic field is called armature reaction.
DC current is not used in transformer?
No. Transformers rely on the magnetic field changing direction to work, so DC can't be used.
What is the function of field winding in DC generator?
The motor needs the current and magnetic flux to create motion The magnetic field is created by field winding where as armature carries the current resulting into the rotation of armature
Why a current wire deflects a magnetic needle placed near it?
A current wire deflects a magnetic needle placed near it because the current wire is creating an electric field. If the current is supplied from an AC (alternating current source as opposed to DC which is direct current- AC would be from a wall socket, DC from a battery), then the current is constantly changing, so the electric field is constantly changing. A changing electric field results in a magnetic field perpendicular (90 degrees) to it. It is actually the magnetic field that is changing the needle direction, because that needle is trying to follow the magnetic field lines (similar to those that you see when you put iron filing near a magnet).
What is armature in motors?
The armature has the stationary (not physically moving) magnetic field, which attracts the magnetic field in the rotor. Since DC does not alternate, a split ring is used to alternate the current (and resulting magnetic field), so that the rotor will spin.
