Fleming’s Left Hand, Right Hand, Maxwell’s Thumb Rule Compared

As explained above, all these different versions (right or left hand, open palm or outstretched fingers) are exactly equivalent as far as the directions are concerned, because magnetic force always acts in the same way.34)35)36)37) In motors, the conventional movement of charges is caused by the conventional current which flows along the conductor in question. The magnetic force will push the conductor in the third orthogonal direction, causing physical movement of the conductor and generation of useful output torque. The middle finger shows the direction of the second vector, which is the direction of magnetic field $B$.

1.1 The Whole-Hand Method

It is used to show the rotation of a body or a magnetic field and represents the connection between the current and magnetic field around the wire. The original “hand rule” introduced by Fleming defined the direction of the induced electromotive force. In the book “Magnets and electric currents” published in 1902, Fleming gave the following description and mnemonics linking letters to names of fingers and variables. In this publication only the right-hand rule was defined, as shown in the illustration.26)

When we use the cross product to calculate the torque due to a force F whose point of application has a position vector r, relative to the point about which we are calculating the torque, we get an axial torque vector τ. To determine the sense of rotation that such a torque vector would correspond to, about the axis defined by the torque vector itself, we use the Right Hand Rule for Something Curly Something Straight. Note that we are calculating the torque with respect to a point rather than an axis—the axis about which the torque acts comes out in the answer. Now rotate your hand, as necessary, about an imaginary axis extending along your forearm and along your middle finger, until your hand is oriented such that, if you were to close your fingers, they would point in the direction of the second vector. If both the direction of movement, and the polarity of charge is reversed, then the force acts in the same direction.

Maxwell’s Right Hand Grip Rule And Right Handed Cork Screw Rule

Right hand rule can also be used for determination of the magnetic field orientation and direction MRI machines use powerful magnetic fields to visualize internal structures in the human body. Understanding the magnetism right hand rule is crucial for optimizing and directing these magnetic fields to obtain clear and accurate images.

Make it easy to learn and understand

  • One of the fascinating phenomena explained by the magnetism right hand rule is electromagnetic induction.
  • Understanding the magnetism right hand rule is crucial for optimizing and directing these magnetic fields to obtain clear and accurate images.
  • We use the right-hand rule when we have two of the axes and need to find the direction of the third.
  • There are many complex topics in the field of physics and right-hand grip rule is one among them.
  • Consider a tilted x-y coordinate system, having an origin on the axis of rotation, with one axis parallel to the line of action of the force and one axis perpendicular to the line of action of the force.

As shown in the illustration, when looking from the end marked with “N”, the current appears to flow in the anticlockwise direction. At the same time, when looking from the end marked with “S”, the current appears to flow clockwise. Calculations of magnetic forces in three-dimensional space involve vector calculus, which by convention operates in a right-handed system, therefore right-hand rules (as outlined above) should be used accordingly. At a fundamental level it is not possible to calculate, in an absolute way, a value for binary quantities such as positive/negative (electric charge), clockwise/anticlockwise (direction of rotation), up/down (side of a surface), etc. They can only be defined with relation to each other, or to some closely related direction in the same system of coordinates.

  • By applying this rule, one can quickly grasp the complex interactions between magnetic fields and electric currents.
  • Rather, the definition depends on chiral phenomena in the physical world, for example the culturally transmitted meaning of right and left hands, a majority human population with dominant right hand, or certain phenomena involving the weak force.
  • When an observer looks at the facing end of the solenoid, if current flows in the clockwise direction, the the facing end of the solenoid coil behaves like the South Pole “S” and the second end behaves like the North Pole “N”.
  • Unlike most mathematical concepts, the meaning of a right-handed coordinate system cannot be expressed in terms of any mathematical axioms.
  • At the same time, when looking from the end marked with “S”, the current appears to flow clockwise.

How Many Panels, Batteries, Charge Controller and Inverter Do I Need?

Unlike most mathematical concepts, the meaning of a right-handed coordinate system cannot be expressed in terms of any mathematical axioms. Rather, the definition depends on chiral phenomena in the physical world, for example the culturally transmitted meaning of right and left hands, a majority human population with dominant right hand, or certain phenomena involving the weak force. A list of physical quantities whose directions are related by the right-hand rule is given below. (Some of these are related only indirectly to cross products, and use the second form.) For left-handed coordinates, the above description of the axes is the same, except using the left hand; and the ¼ turn is clockwise.

Multiplicity of rules in literature

(This assumes you already have a coordinate frame defined to see which axis the wheel is rotating around and which direction). It reveals a connection between the current and the magnetic field lines in the magnetic field that the current created. Ampère was inspired by fellow physicist Hans Christian Ørsted, who observed that needles swirled when in the proximity of an electric current-carrying wire and concluded that electricity could create magnetic fields. When an electric current passes through the coil of wire within a magnetic field, the interaction generates a force that causes the coil to rotate. This rotational motion is the basis of electric motors used in various appliances and industrial machinery. When a conductor moves through a magnetic field, the magnetism right hand rule enables us to predict the induced direction of the current flow in the conductor.

The direction of flux lines of magnetic field, motion of the conductor and induced EMF and current can be found by Fleming’s left hand and right hand rules which we have discussed in the previous post. Beyond its applications in everyday devices, the magnetism right hand rule also helps us comprehend electromagnetic waves, which play a central role in modern communication and technology. Electromagnetic waves consist of electric and magnetic fields oscillating perpendicular to each other, and their direction of propagation is determined by the magnetism right hand rule. Understanding the concept of right-hand grip rule is difficult for many students and so they commit silly mistakes in the examinations like using the left hand for the right-hand grip rule. It should be kept in mind that this rule should only be performed with the right hand. Apart from determining the relationship between current and magnetic field it also shows that moving charges can create magnetic fields.

In some literature this rule is discussed as if it was a separate rule from the one described in the section above, but it results from the same principles. The right hand is depicted with the thumb following the direction of the current in a straight wire, and curled fingers show the direction in which the magnetic field (flux density B or magnetic field strength H) circulating around the wire.19) In simple words, a current carrying conductor creates a magnetic field around it. The lines of magnetic flux are in the shape of concentric circles and perpendicular on the conductor (at right angle of 90o) as shown in fig. The direction of current and magnetic field can be found by the following rules i.e. right hand gripping rule, the end rule, corkscrew rule, Fleming’s left and right hand rules etc.

A positive charge is moving upwards in a magnetic field directed towards the north. By Physics experts to help you in doubts & scoring excellent marks in Class 9 exams. If you find curling your fingers too confusing, you can try this method that uses your thumb, pointer finger, and middle finger all 90 degrees apart. The hardest part of right-hand rule is imagining the different axes and envisioning how they are perpendicular to each other.

This rule is used in two complementary applications of Amperes circuital law which are; when an electric current is passed through a solenoid, a magnetic field is created. The thumb points towards the magnetic field line when the fingers are curled up around the wire in the direction of the flow of current. The right-hand grip rule is used to determine the relationship right hand grip rule between the current and the magnetic field based upon the rotational direction.

Corkscrew Rule

The “hand rules” for directions of magnetic force were proposed in 1890 by John Ambrose Fleming.10)11) All these rules are equivalent, because the direction of the physical magnetic force (Lorentz force) is always the same. From the diagram it is clear that the moment arm r is just the magnitude of the component ┴ vector, in the perpendicular-to-the-force direction, of the position vector of the point of application of the force.

(If the axes do not have a positive or negative direction, then handedness has no meaning.) If you hold the coil or a solenoid in the right hand so that the four fingers curl around the coil or solenoid, then the curly figures show the direction of the current and the thumb represents the North Pole of the coil. The magnetism right hand rule is a concept that underpins electromagnetic interactions.

The magnetism right hand rule plays a vital role in the design and operation of electromagnetic coils in speakers and headphones. The interaction between the current-carrying coil and the permanent magnet creates sound waves that produce the audio we hear. The hardest part of the right-hand rule is imagining the different axes and envisioning how they are perpendicular to each other. This is most likely because the same kind of orthogonality can be represented by various configurations of fingers, on either hand. Fingers can be outstretched orthogonally, or the palm can be flat (hence slap rule). If the electric charge has a negative value (e.g. electron) then the force acts in the opposite direction.

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