Electric & Magnetic Fields Practice Questions Right Hand Grip Rule for Electromagnetism

Then, point your indexfinger in the direction of vector a and your middle finger in the direction of vector b. Your right thumb will pointin the direction of the vector product, a x b (vector c). Normally, for an electromagnetic wave, the electric and magnetic fields, and the direction of propagation of the wave obey the right-hand rule. However, left-handed materials have special properties – the negative refractive index. It makes the direction of propagation point in the opposite direction. Fleming’s left hand rule is a rule for finding the direction of the thrust on a conductor carrying a current in a magnetic field.

Electric Circuits & Electrical Safety

A. Lorentz, a contemporary of Einstein, although its effects were known at the time of Michael Faraday.Now, some people and some books prefer to use the palm to represent the force, that would be current field force (open hand). 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 a straight wire, it induces a magnetic field.

Torques that occur in a counter clockwise direction are positive torques. Alternatively, torques that occur in theclockwise direction are negative torques. Torques thatface out from the paper should be analyzed as positive torques, while torques that face inwards should be analyzedas negative torques.

A conventional current is composed of moving charges that are positive in nature. When a conventional current moves through a conducting wire,the wire is affected by a magnetic field that pushes it. We can use the right hand rule to identify the direction of the force acting on thecurrent-carrying wire.

Lodestones are pieces of the ore magnetite that can attract iron. (The origin of the name is probably not what you think — it’s named after the region, Magnesia, where it was first found). In ancient times, lodestones were so rare and precious that they were worth more than their weight in gold. But these magnets have deflected the electrons from landing on their proper pixels. Normally they just point North, but when I turn the current on we see them all pointing around it, just as we predict with our right hand. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

1. As the current flows upward, the magnetic field will wrap around.
2. To apply the right hand rule to Lenz’s Law, first determine whether the magnetic field through the loop is increasing ordecreasing.
3. The region outside the solenoid has a magnetic field which gradually weakens as you move away from the solenoid (indicated by the increased spacing between the field lines); its shape is also nearly identical to the ‘butterfly field’ of a bar magnet as mentioned above.
4. The field lines seem to begin at the north pole and end at the south pole.
5. Unlike most mathematical concepts, the meaning of a right-handed coordinate system cannot be expressed in terms of any mathematical axioms.
6. Normally they just point North, but when I turn the current on we see them all pointing around it, just as we predict with our right hand.

In this form, the fingers of the right hand are curled to match the curvature and direction of the motion or the magnetic field. 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 right hand grip rule the third or z-axis can point along either right thumb or left thumb.

current community

A cross product, or vector product, is created when an ordered operation is performed on two vectors, a and b. Thecross product of vectors a and b, is perpendicular to both a and b and is normal to the plane that contains it. Sincethere are two possible directions for a cross product, the right hand rule should be used to determine the directionof the cross product vector. The plane formed by the direction of the magnetic field and the charged particle’s velocity is at a right angle to the force. Because theforce occurs at a right angle to the plane formed by the particle’s velocity and the magnetic field, we can use the right hand rule todetermine their orientation.

Magnetic effects of changing current

Since the field lines are emerging from X, we can confidently assert that this is a north-seeking pole, while Y is a south-seeking pole. A current-carrying coil will create a magnetic field as shown below. This also tells us that magnetic monopoles (that is to say, isolated N and S poles) are impossible. Another way to demonstrate this is with the Electricity and Magnetism Light bulb demo. When there is alternating current, the wire vibrates, but when it is direct current we can apply force in a specific direction. Using your right hand, it is possible to predict the direction the current is flowing.

So placing a steel nail in the centre of a solenoid boosts its magnetic field strength by a factor of 100 — which would make the solenoid roughly as strong as a typical bar magnet. Torque problems are often the most challenging topic for first year physics students. Luckily, there’s a right hand ruleapplication for torque as well. To use the right hand rule in torque problems, take your right hand and point it in thedirection of the position vector (r or d), then turn your fingers in the direction of the force and your thumb will pointtoward the direction of the torque. The N and S-poles of a solenoid can change depending on the direction of current flow and the geometry of the loops.

A Physics teacher writes about…stuff.

1. If the velocity of the charged particle is parallel to the magnetic field (or antiparallel), then there is no force because sin(θ) equals zero.When this occurs, the charged particle can maintain its straight line motion, even in the presence of a strong magnetic field.
2. In fact – if you trace the magnetic field with a compass, you can see that it matches the behavior a bar magnet perfectly.Using a third right-hand rule, we can we predict which side of the coil is north.Let your curling fingers be the direction the current is flowing.
3. These are for (1) long, straight wires, (2) free moving charges in magnetic fields, and (3) the solenoid rule – which are loops of current.
4. Another way to demonstrate this is with the Electricity and Magnetism Light bulb demo.

However, we can ‘boost’ the magnetic field by adding an iron core. The relative permeability of a material is a measurement of how ‘transparent’ it is to magnetic field lines. The relative permeability of pure iron is about 1500 (no units since it’s relative permeability and we are comparing its magnetic properties with that of empty space). However, the core material used in the school laboratory is more likely to be steel rather than iron, which has a much more modest relative permeability of 100. De Graaf’s translation of Fleming’s left-hand rule – which uses thrust, field and current – and the right-hand rule, is the FBI rule. The FBI rule changes Thrust into F (Lorentz force), B (direction of the magnetic field) and I (current).

The field lines seem to begin at the north pole and end at the south pole. A helix is a curved line formed by a point rotating around a center while the center moves up or down the z-axis. Helices are either right or left handed with curled fingers giving the direction of rotation and thumb giving the direction of advance along the z-axis.

While a magnetic field can be induced by a current, a current can also be induced by a magnetic field. We can usethe second right hand rule, sometimes called the right hand grip rule, to determine the direction of the magneticfield created by a current. To use the right hand grip rule, point your right thumb in the direction of the current’sflow and curl your fingers. The direction of your fingers will mirror the curled direction of the induced magnetic field.

The direction of the current in the last diagram is shown using the ‘dot and cross’ convention which, by a strange coincidence, I have also written about before . To go in reverse order for no particular reason, I don’t like using the second method because it involves a tricky mental rotation of the plane of view by 90 degrees to imagine the current direction as viewed when looking directly at the ends of the magnet. A solenoid is an electromagnet made of a wire in the form of a spiral whose length is larger than its diameter. The hand rules work the same but they are based on two different current concepts. When choosing three vectors that must be at right angles to each other, there are two distinct solutions, so when expressing this idea in mathematics, one must remove the ambiguity of which solution is meant.