Difference Between Electric Field and Magnetic Field

Electric field and Magnetic Field - Definition and Difference

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 exist 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. DENOTION

  • 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 Electric field whereas, the magnetometer is used to measure the Magnetic field.

  • 5. POLE

  • In an electric field, monopolies (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 called the positron and the negative charge 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, north pole repels 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 was 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.