However, in generators, the charges are originally moved because the wire is pushed by some input torque. The charges move together with the wire, and the magnetic force pushes them along the wire, thus creating an electromotive force (EMF). It should be noted here that the magnetic force for a positive charge always follows this rule, regardless of any other conditions. Therefore, exactly the same right-hand rule is applicable to both motors and generators. For such loop, the magnetic poles N and S appear at each end, and they can be distinguished by the stylised letters with arrows at their ends, which show the apparent direction of “rotation” of current in the loop.
- In the same wire, the electrons would flow from minus to plus, in the opposite direction to the conventional current.
- Right hand rule can also be used for determination of the magnetic field orientation and direction
- 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.
- Similarly, When the observer sees at the facing end of the coil, if current flows in the anticlockwise direction, then the facing end of the coil behaves like a North Pole “N” and the second end behaves like the South Pole “S”.
- A positive charge is moving upwards in a magnetic field directed towards the north.
The index finger shows the direction of the first vector, which in this case is the direction of the original movement of the positive charge $q$ which constitutes conventional electric current $I$. In an ordinary conductor if some voltage is applied across it the electrons will flow in the opposite direction, but it is the conventional current (flowing from plus to minus) which is taken into account here. This is done by using your right hand, aligning your thumb with the first vector and your index with the second vector.
Electromagnetic Coils in Speakers
The magnetism right hand rule helps determine the direction of the magnetic field produced by the solenoid, which is crucial for its applications in valves, door locks, and electromagnetic relays. There are many complex topics in the field of physics and right-hand grip rule is one among them. A student needs to understand the topic and the elements of it in order to learn it. The right-hand grip rule is also known as corkscrew-rule and it was named after the French physicist and mathematician Andre-Marie Ampere.
Similarly, When the observer sees at the facing end of the coil, if current flows in the anticlockwise direction, then the facing end of the coil behaves like a North Pole “N” and the second end behaves like the South Pole “S”. 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”.
Multiplicity of rules in literature
The moment arm can actually be defined in terms of the position vector for the point of application of the force. 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. In which we are looking directly along the axis of rotation (so it looks like a dot) and the force lies in a plane perpendicular to that axis of rotation. We use the diagramatic convention that, the point at which the force is applied to the rigid body is the point at which one end of the arrow in the diagram touches the rigid body. Now we add the line of action of the force and the moment arm r⊥ to the diagram, as well as the position vector r of the point of application of the force.
- We use the diagramatic convention that, the point at which the force is applied to the rigid body is the point at which one end of the arrow in the diagram touches the rigid body.
- 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.
- This logic is consistent with the application of the vector cross product, as explained above for the right-handed system of coordinates.
Coordinates
When viewed at a position along the positive z-axis, the ¼ turn from the positive x- to the positive y-axis is counter-clockwise. The various right- and left-hand rules arise from the fact that the three axes of three-dimensional space have two possible orientations. This can be seen by holding your hands together with palms up and fingers curled. If the curl of the fingers represents a movement from the first or x-axis to the second or y-axis, then the third or z-axis can point along either right thumb or left thumb.
Right Handed Cork Screw Rule
To understand the definition, one must understand the demonstration of the right-hand grip rule. For this, the wire needs to be held in the right hand and the thumb should point towards the direction of the flow of current then curl your fingers around the wire. Now, the curled fingers show the direction of the magnetic field around the wire and how the compass would line-up if placed at that point. The magnetism right-hand rule, also known as the right-hand grip rule, is a powerful tool used to determine the direction of magnetic fields around a current-carrying conductor.
Before we can analyze rigid bodies, we need to learn a little trick to help us with the cross product called the ‘right-hand rule’. We use the right-hand rule when we have two of the axes and need to find the direction of the third. When an electric charge oscillates or accelerates, it emits electromagnetic waves, which travel at the speed of light. Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays are all examples of electromagnetic waves, each having different frequencies and wavelengths. Using these x and y, let’s use the right-hand rule to find the direction of z.
For a three-dimensional system of coordinates also the orthogonality of the three axes can be defined as being “left-handed” or “right-handed”. It has been generally accepted (by convention) that unless stated otherwise the right-hand system is assumed for some calculations published in the literature. This is because certain mathematical functions (such as the vector cross product) would return a negative value if the calculation was made in the opposite system.12)13)14)
From predicting magnetic fields to understanding electromagnetic waves, this rule plays a crucial role in various applications, ranging from everyday devices like electric motors and speakers to cutting-edge technologies like MRI machines and particle accelerators. In particle accelerators, charged particles experience magnetic forces as they move through magnetic fields. Scientists use the magnetism right hand rule to design and control the trajectories of these particles, enabling cutting-edge research in physics. Magnetic compasses are essential navigation tools, and they operate based on the magnetism right hand rule. The compass needle aligns itself with Earth’s magnetic field, indicating the North-South direction. However, nowadays there are publications which refer to the Fleming’s left-hand rule for magnetic force in motors and right-hand rule for generators.27)28)29)
A constant current flows in a horizontal wire in the plane of the paper from east to west as shown in Figure. State a law, which determines the direction of magnetic field around a current carrying wire. State the rule to determine the direction of a current induced in a coil due to its rotation in a magnetic field. State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current. Curl your fingers in the direction of rotation and your thumb shows the direction of rotation. In vector calculus, it is necessary to relate a normal vector of a surface to the boundary curve of the surface.
In fact, in a real wire only the negatively charged electrons move, as the positively charged protons remain bound to the atoms, which are stationary with respect to the body of the wire. The thumb points in the third orthogonal direction, namely in the direction of the magnetic force $F$ acting on the charge moving in magnetic field. P1 and P2 are the positions of the magnetic compass, before and after passing a current through XY respectively.
Right Hand, Left Hand, Thumb Rule – Compared
By applying this rule, one can quickly grasp the complex interactions between magnetic fields and electric currents. This logic is consistent with the application of the vector cross product, as explained above for the right-handed system of coordinates. To find whether the axis of rotation is positive or negative, curl your fingers in the direction of rotation and your thumb shows the direction of right hand grip rule rotation, i.e. whether rotation is along the positive or negative x y or z direction.
The right hand rule is used to determine the direction of the magnetic field lines and current around a straight current carrying conductor, solenoid or coil inductor. A Danish physicist Hans Christian Orsted in 1820 discovered the relation between electricity and magnetism which states that “when current flows in a straight conductor, a magnetic field is produced in it. The polarity and density of the magnetic field depends on the direction and amount of current flowing through the conductor”. One of the fascinating phenomena explained by the magnetism right hand rule is electromagnetic induction. This process occurs when a conductor moves through a magnetic field or when there is a change in the magnetic flux through a circuit. Electromagnetic induction is the foundation of various electrical devices, including generators and transformers.
For example, the illustration on the right shows the situation for a hypothetical positive charge moving from plus to minus due to the current in the wire, and the force acts upwards. In the same wire, the electrons would flow from minus to plus, in the opposite direction to the conventional current. And because two of the variables were changed (polarity of charge and its direction of movement) then the force will still act upwards on such electrons.
There are two ways to do the right hand rule, and they take practice to conceptually understand, but this will make solving problems much quicker. Reversing the direction of one axis (or three axes) also reverses the handedness. Reversing two axes amounts to a 180° rotation around the remaining axis, also preserving the handedness.