Electricity and Magnetism

Electricity and magnetism are ultimately inextricably linked. Electricity is the term given to a group of physical phenomena involving electric charges, their motions, and their effects. Magnetism is the force generated by the passage of an electric current through matter.

9,396 Questions
Electronics Engineering
Physics
Electricity and Magnetism
Circuits

What are the factors on which resistance depend?

It depends on the intermolecular structure of the individual material. It varies for various material.

Generalised formula for calculating the resistance of any material is :

R = k* L/A

Where

R = Total Resistance.

K = Specific Resistance of the material.

A = cross-sectional area of material for which resistance is measured.

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Electricity and Magnetism
Electromagnetic Radiation
Waves Vibrations and Oscillations

How electromagnetic wave produced?

electromagnetic waves are produced by the changes in the sub atomic level when heat or electricity is applied to an atom electron which is present in lower energy level will obsorbs energy and jumps in to higher energy level after that it again jumps in to lower energy level.when the electron is jumping in to lower energy level it emitts energy in the form of photons.these transmission of photons is said to be electromagnetic waves.in the electromagnetic waves electric and magnetic fields are perpendicular to each other and also perpendicular to the direction of wave propagation.

EM waves can also be produced by the action of a radio-frequency current in an antenna. Radio transmitters produce power at a single frequency and the antenna acts as a tranducer taking the power from the transmitter and converting it into power that is radiated into space and can be received at a distant point.

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Home Electricity
Electricity and Magnetism
Batteries

Is a battery considered electricity?

The battery is not electricity. A battery is a device that stores energy in the form of

chemical energy.

When energy is taken out of the battery, it comes out in the form of electrical energy.

And if the battery is rechargable, then energy is put into it also in the form of electrical

energy.

A2.

There is sometimes a confusion, amongst non-technical people when discussing electrical items. A distinction is made between an AC mains operated device and a battery operated device. Calling the mains device 'electric' and the other 'battery'.

A battery operated device is also 'electric', The current is DC and the voltage usually a lot lower (and safer) than the domestic supply.

So yes. A battery operated device is electric. Batteries do produce electricity.

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Physics
Electricity and Magnetism
Electrostatics

Is your body a conductor?

Yes it is. It isn't a very good one but the water and ions in your body allow currents to flow. If your body was a perfect insulator, nobody would ever get an electric shock.

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Science
Electricity and Magnetism

Why must pylons have ceramic discs?

Pylons must have ceramic or glass insulators to support overheard lines; this prevents the pylons from becoming "live."

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Physics
Chemistry
Electricity and Magnetism

Does mercury from thermometer kill a person?

Mercury is a highly-toxic metallic liquid that can be dangerous through contact, ingesting, or breathing of its fumes. I don't know if the amount in a thermometer can kill a human being.

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Science
Electricity and Magnetism

DEscribe what happens to parallel light rays hitting concave mirror?

You mean parallel rays to the principal axis of the concave mirror!

After reflection at the concave surface of the mirror they would get converged at a point on the principal axis of the mirror. This point is known to be the focus.

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Units of Measure
Electricity and Magnetism
Magnetism

Magnetic induction unit?

tesla

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Electricity and Magnetism
Magnetism

What does the term induced magnetism mean?

In the simplest terms, Induced Magnetism is magnetism of an object as a result of an external influence. Typically, the external influence is a magnetic field due to another object.

Though this is a technical term, it has a meaning that is the normal meaning of "induced," as in "caused by." This is to be contrasted with other modifiers, like "permanent magnetism" or "remnant magnetism" or "spontaneous magnetism" which are all still magnetism of an object but with a modifier further describing the magnetic state. (One also hears the term transient magnetism applied to the same phenomenon. To be considered transient, the magnetism must disappear when the external influence disappears, but to be "induced" it just has to appear.)

If one is being more technical, then in scientific circles the term "induced magnetism" usually refers the situation where an object acquires a magnetic field as a result of it being in some external magnetic field even though it is not normally a magnetized material. One see this all the time. If you bring a permanent magnet near a collection of paperclips, then the paperclips all attach to one another and to the permanent magnet. Each paperclip has become, temporarily, a magnet. If the permanent magnet is removed, the paperclips no longer attach to one another. The magnetic properties of the paperclips were "induced" and not a permanent characteristic.

More technicalities can be present with this term, because magnetism in an object can be induced in other ways than the application of a magnetic field. In the absence of such technical considerations, it is safe to assume that the term "induced magnetism" just means a temporary state of magnetization of an object induced by an external magnetic field provided by a permanent magnet or an electromagnet.

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Home & Garden
Electricity and Magnetism

What is a power fuse unit?

In electronics and electrical engineering a power fuse is a type of sacrificial overcurrent protection device. Its essential component is a metal wire or strip that melts when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overload or device failure is often the reason for excessive current.

A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented. Wiring regulations often define a maximum fuse current rating for particular circuits. Overcurrent protection devices are essential in electrical systems to limit threats to human life and property damage. Fuses are selected to allow passage of normal current and of excessive current only for short periods.

In 1847, Breguet recommended use of reduced-section conductors to protect telegraph stations from lightning strikes; by melting, the smaller wires would protect apparatus and wiring inside the building. [1] A variety of wire or foil fusible elements were in use to protect telegraph cables and lighting installations as early as 1864

A fuse was patented by Thomas Edisonin 1890 as part of his successful electric distribution system.

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Electricity and Magnetism

How do dynamos work?

Mechanical energy is changed into electrical energy in case of dynamo. When a coil of wire is rotated in the vicinity of magnetic field then magnetic flux will be cut. This would cause an induced emf in the coil and this phenomenon is known as electromagnetic induction.

AnswerThe movement of another body is transmitted to a rectangular coil of wire that is inside a U-Shaped magnet. The motion of this coil of wire cuts the magnetic flux in the magnet. Faraday once stated that-Whenever there is a change in magnetic flux linked with a circuit there is an induced current and the strength of this induced current is directly proportional to the rate of magnetic flux-. So according to this rule when the magnet is in motion it is constantly cutting the magnetic flux, and as it does this there is a current that is induced (eddy currents). However a dynamo can either be A.C or D.C according to the brushes and number of commutators used (Flemings Right-hand rule). If we refer back to Faraday's rule it says that the strength of this induced current is directly proportional to the rate of magnetic flux. This rule can be seen practically in a bicycle that has a dynamo. The faster the rider rides the faster the change in magnetic flux and hence the brighter the light

Dynamo is just the opposite/ reverse action of motor operation.

When a conductor is moved across a magnetic field, there induces an emf (voltage) across conductor terminals so as it opposes the change of flux (Lenz rule).

Dynamo is constructed with a cylindrical permanent magnet (which rotates at the center) amidst windings that we take the voltage output from. when the magnet rotates its flux path changes relative to the windings and across the winding there exists an electro-motive-force as a voltage..
You know,the one about a coil of wire, with a changing magnetic field inside of it, with the induced voltage proportional to the number of turns of the coil, and also proportional to the rate of change of the magnetic flux through the coil.

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Electricity and Magnetism

Is rubber is a bad conductor of electricity?

Yes this is because electricity cant run through it very well

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Home Electricity
Electricity and Magnetism
Batteries

How is direct current stored in a battery?

Direct current is also used for other things. It is not used only to store in batteries.

--------

A battery can only produce a potential difference between it's terminals, caused by chemical action. So this is Direct Current.

The poles of the battery are permanently one positive (+) and one negative (-).

To put power back into a battery, the voltage must match with the + and - terminals. If the voltage is reversed (as in an AC supply), then the charge will be removed from the battery instead of being added, at each half cycle.

To charge a battery from an AC supply, it first has to be rectified. This can be done simply by passing the current through a rectifier, which will make sure that current of one potential only, will be passed on to the battery.

Alternating current is normally produced by a mechanically rotating field, generated by turning a shaft with coils of wire mounted on it.

Alternating current can also be produced electronically from a DC (battery) supply. This generally involves transistor switches, which vary the current to simulate an alternator. This device is known as an 'Inverter'.

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Physics
Electricity and Magnetism

What is the force that pushes objects apart?

There's no force that pushes electrically neutral objects apart, but if the objects in question have a net charge, then the force known as electromagnetism will either push similarly charged objects apart, or pull oppositely charged objects together.

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Electricity and Magnetism
Electronics

What are the three electrical quantities?

Voltage , volts

Current , amperes

Resistance, ohms

Answer There are numerous electrical quantities, not just three. They include, current,

charge, voltage, resistance, inductance, capacitance, frequency, power, energy,

reactance, impedance, admittance, susceptance, conductance, permeability,

permittivity, resistivity, conductivity, etc.

<<>> For basic definitions of dimensions in physics, it is normal to take mass, length, time and charge (MLTQ); or mass, length, time and current (MLTI). Thus only one extra physical dimension is needed to extend normal mechanical space to include electrical quantities.

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Electricity and Magnetism

What is the retarding force?

The spring is good example... If you compress spring you feel force which tries to restore to its previous condition, or if you stretch it you feel force which tries to bring the spring back to normal size. The force which is responsible for both is retarding force.

Or if you put three charges of the same sign and fix two at the ends the system will end up in some kind of equilibrium. The middle charge will be somewhere in between. Know if you push the charge in any of sides you will force which is trying to push the charge back. The force you fill is retarding force.

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Chemistry
Electricity and Magnetism

Can a galvanised iron nail become a electromagnet?

Yes, a galvanized nail is still made mostly of iron or steel. The galvanization is merely a coating of zinc.

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Home Electricity
Electricity and Magnetism

Relationship between the length of wire and its electric current?

Is called resistance. Increasing length leads to more resistance that in turn leads to less current.

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Electricity and Magnetism
Electrical Engineering
Magnetism

What is cross magnetization?

In spirituality, cross magnetization occurs when two mediums treat a patient at the same time.

In physics, specifically electromagnetism, cross magnetization occurs when the flux-density distribution of the magnetic field that's defining the neutral plane gets distorted by a secondary magnetic field, known as the armature field. This distorting effect, which effectually changes the direction of the neutral plane, is called the armature reaction drop, and is controlled by varying the current through whichever of the two magnetizing devices was designed as the electromagnet.

217218219
Physics
Chemistry
Electricity and Magnetism

Is graphite conducts electricity is an example of chemical or physical change?

No. It's just a quality of graphite, which is always true. A change is when there's a difference between before and after.

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Earth Sciences
Information Science and Libraries
Electricity and Magnetism

What are five uses of electromagnets?

They can be used in cranes to lift heavy metals

They can be used in electric bells

They can be used in radio speakers

Can be used in microphones

They can be used in dynamos

They can be used in cranes to lift heavy metals

They can be used in electric bells

They can be used in radio speakers

Can be used in microphones

They can be used in dynamos
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Chemistry
Electricity and Magnetism

What is hafniums conductivity?

Electrical resistivity of hafnium: 331 nanoohms.m

207208209
Technology
Electricity and Magnetism

What energy transformation occurs in the television?

In a TV electrical energy is converted primarily into sound and light energies but also heat as a by product of the first two transformations.

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Home Electricity
Personal Safety and Security
Electricity and Magnetism

Is it safe to vacuum clean wet bathroom floor?

It is safe to vacuum a clean wet bathroom floor only if you use a wet vaccuum designed for that purpose. If you just use a regular vaccum, you run the risk of short-circuiting your vacuum and damaging the insides.

Other Safety Tips:

  • Even with wet-dry vacuums, make sure the insulation on the cord is in good condition without any breaks or signs of wear.
  • Try not to stand in the water, if you can help it. Definitely while plugging in (or unplugging) and switching on/off.
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Electronics Engineering
Physics
Electricity and Magnetism
Particle Physics

When will the flow of protons be involved in an electrical circuit?

In metallic conductors, current is produced by flow of electrons.

Usually , protons are not involved in an electrical circuit, however, in case of electrolysis of aqueous NaCl, Positive ions which are protons act as charge carriers and become cause of flow of electric current.

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