Is Electric Field Strength A Vector? 5 Facts You Should Know

The electric field has a magnitude and a direction. Let us see whether the intensity/ strength of the electric field is a vector quantity or not in this article.

The electric field strength has a vector, and it cannot be wholly defined without a direction. The direction of the electric field strength is relative to the direction of electric flux and the force because the electric field strength is directly proportional to both these quantities.

The electric field strength is found by knowing the total amount of the electric flux penetrating through the area of a conducting region. Lets us discuss further in this article the different factors responsible for the vector quantity of the electric field strength and its direction.

Why is electric field strength a vector quantity?

A vector quantity has a direction along with the magnitude. Let us intricate over whether the electric field strength also has a direction or not.

The electric field strength is defined as a vector quantity because the strength of the field depends upon the force exerted by the electric flux on the charge that has a direction and the magnitude of the charge that generates the electric field region surrounding it.

The electric field strength is not a scalar quantity as it has a specific direction due to the presence of force. It is estimated as the force per unit charge and measured in Newton /Coulomb (N/C).

What is the direction of electric field strength?

The direction of the electric field strength depends upon the particle’s charge. Let us see how the charge decides the direction of electric field strength.

The direction of the electric field points away from the charge if it is negative and is directed towards the charge if it is positive. The direction of the electric field strength is parallel to the electric force experienced on the charge.

The electric field strength direction is along the electric force on the positive charge, while the same is pointing in the opposite direction yet parallel in the case of a negative charge. Since the electric field strength is opposite to the force, it is denoted with a negative sign.

What is the magnitude of the electric field strength?

The magnitude of the electric field strength tells about the immensity of the electric field produced by a charge. Let us now discuss the same ahead.

The electric field strength is calculated using the formula E = F/q, where q is a charge, F is a force incident on it, and E is the electric field strength. The electric field strength magnitude is always positive irrespective of its direction and type of charge.

The magnitude of the electric field strength is also expressed as E = k (q)/r2, where k is the electric constant equal to (9×109 Nm2/C2), q is a charge, and r is the distance between a charge and a point.

If the electric flux density is high in that field, more force is felt on the charged particles. Hence, the magnitude of the electric field strength is also proportional to the number density of electric flux.

What is the magnitude of electric field strength produced by +2 C and -4 C at a point 2 m away from both charges?

Given: The charge q = +2 C.

The charge Q = -4 C.

The distance between the point and the charges is r = 2 m.

The expression for the electric field strength is given as,

E = k q/r2

By substituting values in the above expression, we get the electric field strength due to charge q at a point located 2 m away from it as,

E1 = 9×109 Nm2/C2 × (+2 C)/(2 m)2

= 9×109 Nm2/C2 × (2 C/4 m2)

= 9×109 Nm2/C2 × C/2m2

= 4.5×109 N/C

Now, the electric field strength due to charge Q at the same point is,

E2 = 9×109 Nm2/C2 × (-4 C)/(2 m)2

= -9×109 Nm2/C2 × (4 C/4 m2)

= -9×109 Nm2/C2 × C/m2

= -9×109 N/C

Hence, the magnitude of the electric field strength produced at a point due to these two charges is,

E = l E1 + E2l

= l(4.5×109 N/C) +( -9×109 N/C) l

= l(4.5 – 9)×109 N/C l

= l(-4.5×109 N/C l

= 4.5 ×109 N/C

Hence, the magnitude of the electric field strength at a point 2 m away from both charges is 4.5 ×109 N/C.

Does the direction of the electric field strength depend upon the electric flux?

The electric field strength is directly dependent on the density of the electric flux. Let us ponder how the electric field strength direction is based on electric flux.

The direction of the electric field strength is primarily dependent upon the electric flux orientation and lies along the same direction that of the flux. The electric field strength is a ratio of electric flux per unit area.

The electric field strength directly resembles the intensity of a field. The direction of the electric flux is towards and away for the positive and a negative charge, respectively, and so is the direction of the electric field strength.

Conclusion

The electric field strength is the electric flux per unit area measured as force per unit charge. Since electric flux and the force has direction, the electric field strength is a vector quantity. The direction of the electric field strength is determined by the type of charge and its magnitude.

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