Definition and Differences Between Electrical Field and Magnetic Field
In this article, you will find the proper explanation of what an electric field and a magnetic field are. The differences have been pointed out in simpler language for a better understanding of the students. Check the explanation and develop your conceptual foundation in this topic exceptionally.
What is the Electric Field?
Electric field or electric field intensity is the force surrounding an electrically charged particle. We can also say that it is the area where the line of force exists and these lines of force surround the electric field. These lines of force are imaginary lines that are used to define the area of influence around the electric charge. It is a vector quantity as it has both direction and magnitude. The symbol used to express the electric field is the letter E. It's unit of measurements is Newton/Coulomb.
What is the Magnetic Field?
The area around the magnet where attractive forces or repulsive forces are exhibited by the poles of the magnet is called magnetic field. When electric charges move across space or an electrical conductor, a magnetic field is induced due to its motion.
Comparing the Two Fields
1. Unit
The unit for Electric field is Volt/meter or Newton/coulomb.
Whereas, the unit for Magnetic field is: Tesla, (Newton × Second)/(Coulomb × Meter)
2. Denotation
The electric field is denoted by E
The magnetic field is denoted by B
3. Formula
The formula of Electric Field, = Newton/ Coulomb (N/C)
Whereas, the formula of Magnetic field, = Tesla or wb/m2
4. Measuring Instrument
An electrometer is used to measure the electric field whereas the magnetometer is used to measure the Magnetic field.
5. Pole
In an electric field, monopoles (single charges) exist. In an electric field single positive and negative charges exist. For monopoles, like positrons and electrons, there are straight field lines either towards or away from the charge.
In a magnetic field, only dipoles exist. Monopoles do not exist. This is because magnetic field lines start from the north pole and end at the south pole. Therefore, magnetic fields have both poles i.e. dipoles only.
6. Electric field and magnetic field are perpendicular to each other. The electric field is perpendicular to the magnetic field and vice-versa.
7. Field lines are imaginary lines that define the area where the force or influence of the charge is effective. This charge can be an electric charge or a magnetic dipole.
For an electric charge, the field lines are straight. For a position, they are outwards and for an electron, they are inwards.
For a magnetic dipole, they start at the north pole and terminate on the south pole.
8. The field is the area of influence around any charge or magnet. Both electric and magnetic fields are vectors. They have directions and magnitude.
9. The electric field is defined by straight field lines. They do not form closed loops.
Magnetic field lines form a closed loop starting from the north pole and terminating at the south pole outside the magnet.
10. There are two types of charges present in an electric field. The positive charge is called the positron and the negative charge is called the electron.
11. The force between the charges is the same. Like repels like. A positron repels a positron but attracts an electron. Same way, the north pole repels the north pole but attracts the south pole.
12. Dimensionally, an electric field exists in two dimensions whereas magnetic fields exist in three dimensions.
13. Work is done by the field when a particle enters its field of influence.
The electric field can do work. When a particle enters an electric field, the electric field can influence the particle by changing its velocity as well as its direction.
The magnetic field cannot do any work. When any particle enters the area of influence of a magnet, the magnet field cannot affect the velocity or direction of this particle. Basically, the work done by a magnetic field on a particle is zero.
Brief About the Discovery of the Electron and its Ramifications
The finding of the electron in 1898 brought up a whole new field of study: the nature of the electric charge and of matter itself. The finding of the electrons came out of the research of electric flows in vacuum tubes. Heinrich Geissler, a glassblower who aided the German physicist Julius Plücker, developed the vacuum tube in 1854. From then till the end of the century, the characteristics of cathode-ray discharges were investigated thoroughly.
Crookes believed that the rays were composed of electrically charged particles. In 1898 another English physicist, Sir J.J. Thomson defined a cathode ray as a stream of negatively charged particles. Each of these were having a mass of 1/1836 less than that of a hydrogen ion. Thomson’s finding confirmed the particulate nature of the charge; his particles were eventually termed electrons.
FAQs on Difference Between Electric Field and Magnetic Field
1. What was faraday’s discovery of electric induction?
Faraday, the finest experimentalist in electricity and magnetism of the 19th century and one of the best practical scientists of all time, labored on and off for 10 years attempting to establish that a magnet could produce electricity. In 1831, he eventually achieved this by employing two coils of wire coiled around opposing sides of a circle of soft iron.
The initial coil was hooked to a cell; as the power went through the coil, the iron band became magnetic. A wire from the other coil was stretched to a magnetic needle a meter distant, far sufficiently so that it was not influenced immediately by any power in the first circuit. When the first circuit was switched on, Faraday noticed a transient deviation of the magnetic needle and its quick restoration to its former position.
When the main power was shut off, a comparable deviation of the magnetic needle happened but in the other direction. He also proved that an electric current may be created by rotating a magnet, by switching an electromagnet on and off, and even by moving an electric wire in Earth’s magnetic field. Within a few months, Faraday created the first, albeit rudimentary, electric generator.
2. Who discovered the concept of the magnetic field?
By the end of the 18th century, researchers had identified multiple electrical occurrences and some magnetic events, but most felt that these were separate energies. Hans Christian was schooled mostly at home and exhibited significant curiosity in science as a kid. At age 13 he dedicated himself to his father, a pharmacist. In 1794, he attended the University of Copenhagen. He there studied physics, philosophy, and pharmacy, and got a Ph.D. in philosophy.
Oersted made the finding for which he is famous in 1820. For example, it had long been known that a compass, when hit by lightning, might switch polarity. Oersted had earlier recognized a resemblance between thermal radiation and light, however, he did not discover that both are electromagnetic waves. He thought to have reasoned that electricity and magnetism were impulses created by all materials. These powers may also indeed interact with one other.
3. What is maxwell’s unified theory of electromagnetism?
The last advances in merging electricity and magnetism into one logical framework were completed by Maxwell. He was strongly impressed by Faraday’s work, having begun his research of the phenomenon by converting Faraday’s experimental discoveries into mathematics. In 1856 Maxwell provided the hypothesis that the power of the electromagnetic wave originated in the environment around the lines including in the connections themselves.
By 1864 he already formulated his proposed electromagnetic theory of light. He argued that both light and radio waves are electric and magnetic occurrences. While Faraday had established that variations in magnetic fields create electric fields, Maxwell emphasized the converse: changes in electric fields cause magnetic fields even in the lack of electric flows. Maxwell anticipated that electromagnetic waves flowing through empty space have electric and magnetic fields at right angles to each other and that both fields are perpendicular to the path of the wave.
He reasoned that the waves travel at a consistent pace equivalent to the pace and that light is one sort of electromagnetic wave. Their clarity, however, Maxwell’s bold theories were recognized by few outsiders, England until 1886, when the German scientist Heinrich Hertz established the reality of electromagnetic waves traveling at the speed of light; the waves he found are known now as radio waves.
