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THUMB RULE:
If we put our one thumb in the direction of magnetic flux passes through the conductor,then the movement of the fingures denotes the direction of current flow.
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∙ 16y ago
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What is the principle of motor action?
Motor runs by the principle of Michael Faraday's Electromagnetic Induction. It is defined as "when a current-carrying conductor is located in an external magnetic field perpendicular to the conductor, the conductor experiences a force perpendicular to itself and to the external magnetic field". The direction of rotation is determined by the Right-hand Rule and is "if the right thumb points in the direction of the current in the conductor and the fingers of the right hand point in the direction of the external magnetic field, then the force on the conductor is directed outward from the palm of the right hand".
What is the shape of the magnetic field that surrounds a current carrying wire?
The shape of the magnetic field created by current flow in a wire will be circular around the wire. The magnetic lines of force "surround" or "wrap around" the wire according to the left hand rule. Grab the wire with your left hand with your thumb extended and pointing in the direction the electrons are flowing. The fingers will be wrapping around the wire in the direction of the magnetic field. Look at the wire "head on" and picture the electrons "coming at you" as you look. The magnetic lines of force will circle around the wire in a clockwise direction. Grab the wire with your left hand as you look "into" that wire and look at your fingers. Clockwise. The magnetic lines of force "circle" the conductor in closed rings. temptress_skkk: In my textbook, it says the "right-hand rule" instead of the "left-hand rule" but it's basically the same thing, only the current is going the opposite way with your right hand instead of your left hand being in its place. it is the right hand rule of thumb not the left hand. and the magnetics line will fade as the square of the distance.
What is flaming left hand rule?
Stretch the thumb the first finger and the central finger of the left hand so that they are mutually perpendicular to each other. If the first four finger points in the direction of magnetic field the central finger points in the direction of current then the thumb points in the direction of motion of the conductor is known as fleming's left hand rule. by Prosenjit.
Why direction of rotation is not reversed when both field and armature terminals are reversed?
The direction of the force that drives the machine is determined by the relative directions of the field and the armature current. By reversing the direction of both field and the armature current, the direction of the resulting force stays the same; you have to reverse the direction of one or the other; not both! Prove it for yourself, by applying Fleming's Left-Hand Rule (for conventional current flow); reverse the direction of both your first finger (field) and your second finger (armature current), and you thumb (direction of motion) will end up pointing in the same direction!
What is the phase current of a three phase 2.2kw 415v motor connected in star?
The line current would be the same if the motor were connected in delta. The current can be based on the rule of thumb which says 7 amps must be allowed for a 1-HP single-phase motor on 240 v. A 2.2 kW motor is three times as powerful, and on a three-phase supply of the same voltage (240/415) it would draw 7 amps.
How rigt hand thumb rule is used in determining the direction of magnetic field around a conductor carrying current?
Curl the fingers of your right hand into the palm and extend the thumb. The thumb indicates the direction of the current, and the direction of the fingers indicates the direction of the magnetic field.
How is the left-hand rule related to current and magnetic field?
It is related to the flow of electrons in a conductor through aseparate magnetic field. If you point your index finger straight place your thumb up and place your middle finger at a 90 degree angle to the other two (unless you are really double jointed there is only one way to do it.). The direction of current and your wire is the middle finger the direction of magnetic plane pointing north is your index finger and the direction of force is your thumb. There is also the right hand rule. If you look at your right hand with your thumb up and fingers curved, If you held a piece of wire in your hand with the current traveling along the direction of your thumb the magnetic field would rotate in the direction of your fingers.
What shape do magnetic field lines have around a wire with a steady current in it?
a circle. using your right hand, if you point your thumb in the direction of the current, your fingers will curl around the wire in the shape of the magnetic field.
Which law gives the direction of magnetic field due to a current carrying conductor?
The right hand rule. If you were to place your right hand around the conductor, with the thumb pointing in the direction of current flow, your fingers which are wrapped around the conductor will point in the direction of magnetic flux. Said another way, if you are looking at the end of the conductor and current is flowing towards you, then magnetic flux will be counter-clockwise.
What law states that the induced current is always in such a direction as to oppose the change in the magnetic field that generated it?
It is called Lenz's law. Refer to the below related link for its Wikipedia article. It is a direct result of Faraday's law. If you look at the equation.. ε = - dΦ/dt it is basically the negative sign that says the magnetic field of the induced current will be in the oppose direction of the change in the magnetic field. Do the following things. • Curl the fingers of your right hand. • Let your thumb represent the direction that the magnetic flux is increasing. • Because of the negative sign, the electric field, and thus the generated current will be in the opposite direction of you fingers. • So flip your hand over so that your fingers point in the opposite direction. • Now your thumb points in the opposite direction and that represents the direction of the magnetic field that the current generates.
What is the purpose of Fleming's right hand rule?
Fleming's right hand rule is used to determine the direction of the magnetic force on a current-carrying conductor in a magnetic field. By aligning the thumb with the direction of current flow, the forefinger with the direction of the magnetic field, the middle finger points in the direction of the magnetic force acting on the conductor.
How do you decide the 'Direction of Rotation' of a magnetic field?
There is a convenient rule called the "right hand grip rule":If you grip your right hand around the electric conductor with your thumb pointing in the direction the current is flowing, the magnetic field rotates in the direction your remaining fingers are pointing.See related Wikipedia link for an illustration.
What is the direction of the magnetic field if the current is directed upward or downward?
The direction of the magnetic field is counterclockwise or clockwise. For a current flowing in a wire you can use the "left hand rule" If you take your left hand and have the thumb point in direction of electron flow in the wire, the fingers wrapped around the wire will show the direction of the magnetic field by the direction the fingers are pointed..
What shape is magnetic field produced when current is passed through the wire?
it is called the thumb rule right hand curled means flux line thumb means direction of current. there will be a reversal of flux.
Suppose that you're facing a straight current-carrying conductor and the current is flowing toward you the lines of magnetic force at any point in the magnetic field will act in?
The lines of magnetic force at any point in the magnetic field of a current flowing towards you will act in the counter clockwise direction. This can be determined by using the right hand rule. Point your thumb in the direction of the current flowing down the straight wire. The curl of your fingers shows the direction of the magnetic lines of flux. The magnetic field of a current is always perpendicular to it. A current facing away from you would produce magnetic lines of force acting in the clockwise direction.
How will you describe the magnetic field around a straight current carrying wire?
Yes, if you place your thumb in the flow direction, the magnetic direction around the wire will be ccw.
What produce by the flow of electric charge from one area to another?
When electric charge flows from one place to another, it induces a magnetic field. The direction of the magnetic field is found by the right hand rule. To use the right hand rule, put your right hand into a fist with your thumb pointed up. When your point your thumb in the direction of the current, and the direction your fingers gives you the direction of the magnetic field.
