What is the difference between magnetic field and magnetic field lines?

Jasmine Grover logo

Jasmine Grover

Education Journalist | Study Abroad Strategy Lead

Magnetic fields and magnetic field lines are related to each other and are used to describe the behaviour and properties of magnetic fields. The main differences between magnetic fields and magnetic field lines are as follows – 

Magnetic Field Magnetic Field Lines
Magnetic field is a vector quantity that describes the strength and direction of the magnetic force on a charged particle or a magnetic material. Magnetic field lines are a visual representation of the direction and strength of the magnetic field in a given region of space.
Magnetic field is measured in Tesla (T) or Gauss (G). Magnetic field lines have no units.
Magnetic field is continuous and exists throughout a region of space where a magnetic field is present. Magnetic field lines are discrete and do not exist outside the region where a magnetic field is present.
Magnetic field lines point in the direction of the magnetic field at any given point in space. Magnetic field lines are a closed loop that begins and ends on magnetic poles.
The strength of the magnetic field can be calculated at any point in space by measuring the magnetic field vector. The density of magnetic field lines indicates the strength of the magnetic field, with closer lines indicating a stronger field.
The magnetic field is used to calculate the magnetic force on a charged particle or a magnetic material. Magnetic field lines are used to visualize and represent the direction and strength of the magnetic field in a given region of space.

In summary, the magnetic field is a mathematical vector that describes the strength and direction of the magnetic force, while magnetic field lines are a visual representation of the magnetic field that provides information on the direction and strength of the magnetic field at different points in space.

Read More:

CBSE CLASS XII Related Questions

  • 1.
    In a Young's double-slit experiment, two waves each of intensity I superpose each other and produce an interference pattern. Prove that the resultant intensities at maxima and minima are 4I and zero respectively.


      • 2.
        A part of a wire carrying \( 2.0 \, \text{A} \) current and bent at \( 90^\circ \) at two points is placed in a region of uniform magnetic field \( \vec{B} = -0.50 \, \hat{k} \, \text{T} \), as shown in the figure. Calculate the magnitude of the net force acting on the wire.


          • 3.
            Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side \( a \), kept on a table and carry equal current \( I \). The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude:

              • \( \dfrac{\mu_0 I}{\pi a} \) and directed along OC
              • \( \dfrac{\mu_0 I}{\pi a \sqrt{2}} \) and directed along OD
              • \( \dfrac{\mu_0 I \sqrt{2}}{\pi a} \) and directed along OB
              • \( \dfrac{2\mu_0 I}{\pi a} \) and directed along OA

            • 4.
              The magnetic field in a plane electromagnetic wave travelling in glass (\( n = 1.5 \)) is given by \[ B_y = (2 \times 10^{-7} \text{ T}) \sin(\alpha x + 1.5 \times 10^{11} t) \] where \( x \) is in metres and \( t \) is in seconds. The value of \( \alpha \) is:

                • \( 0.5 \times 10^3 \, \text{m}^{-1} \)
                • \( 6.0 \times 10^2 \, \text{m}^{-1} \)
                • \( 7.5 \times 10^2 \, \text{m}^{-1} \)
                • \( 1.5 \times 10^3 \, \text{m}^{-1} \)

              • 5.
                A circular coil of 100 turns and radius \( \left(\frac{10}{\sqrt{\pi}}\right) \, \text{cm}\) carrying current of \( 5.0 \, \text{A} \) is suspended vertically in a uniform horizontal magnetic field of \( 2.0 \, \text{T} \). The field makes an angle \( 30^\circ \) with the normal to the coil. Calculate:
                the magnetic dipole moment of the coil, and
                the magnitude of the counter torque that must be applied to prevent the coil from turning.


                  • 6.
                    A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

                      • 5 V
                      • 3.5 V
                      • 2.5 V
                      • Zero V
                    CBSE CLASS XII Previous Year Papers

                    Comments


                    No Comments To Show