Is Electric Current a Scalar or a Vector Quantity? Answered

Physical quantities have two types vector and scalar quantities. The vectors are the quantities that have a certain direction and a magnitude. The scalar quantities have only magnitude. For example, electric currents have a direction and a magnitude. So, is electric current a scalar or a vector quantity?

Is Electric Current a Scalar or a Vector Quantity?

The electric current is a scalar quantity, but it has a direction and magnitude; the current is the electrons’ flow rate in a conductor. The ampere is the unit used for electric current. Physical quantities are vector quantities because they have a direction and a magnitude.

However, the vector and scalar quantities can also be determined by other factors; for example, if the vector laws can be applied to them, such as the parallelogram law of vector and the triangle law of vector, then the physical quantity is a vector quantity.

Why Are Electric Currents Scalar Quantities?

The main reason to consider the electric current as a scalar quantity is that it doesn’t apply to vector summation. The resultant will be calculated using the algebraic sum if a current meets another current. Therefore, the electric currents are considered scalar quantities, but they have direction and magnitude.

The current doesn’t obey the vector’s laws of summation, but it obeys the scalar’s laws of summation. In addition, the total current is not affected by the angle between the wires; the direction of the electric current refers to the positive charge flow direction.

Related Readings:

What Color Wires Can Go Together? Complete Guide

Why Voltage Decreases When Current Increases?

What Happens When a Wire Is Stretched To Double Its Length?

How To Identify Positive and Negative Terminal of DC Motor?

Why Do Parallel Resistors Have Less Resistance?

How To Identify a Ring & Radial Circuit? SOLVED

Physical Quantities (Scalar and Vector)

Physical quantities are used to explain every scientific explanation; each quantity has a particular meaning and is great. According to scientific description, each physical property that has a piece of specific information and can be quantified and measured is called a physical quantity. The direction is the main factor in classifying quantities.

The properties can have either a direction and a magnitude or only magnitude, for example:

  • Scalar
  • Vector

What Is Scalar Quantity?

Any quantity with no direction but the only magnitude is a scalar quantity; the magnitude is simply a value with a corresponding unit. Scalar quantities examples are:

  • Mass
  • Length
  • Speed
  • Duration

They have no specific direction, the scalar quantity has the same value in any direction, so they are one-dimensional parameters. So magnitude is the only thing affected by a change in the scalar quantity because they have no direction. So when two scalar quantities are combined, they can be calculated through typical algebra.

The numbers can be multiplied, subtracted, or added; the same goes for the scalar quantities; if the quantities have the same unit, they can typically obey algebraic law. For example, a dot product is the multiplication of two or more scalar quantities.

What Is Vector Quantity?

Quantities with magnitude, unit, and a particular direction are called vector quantities, so when defining a vector quantity, you must know its specific direction and the magnitude value. Vector quantities examples are:

  • Force
  • Velocity
  • Displacement 
  • Weight

In vector quantities, the magnitude refers to the quantity size, known as the quantity’s absolute value; meanwhile, the north, south, east, and west are the directions. The vector quantities can be expressed in three parameters one-dimensional, two-dimensional, and three-dimensional.

When a change is applied to a vector quantity, it can affect either direction change, magnitude, or both. The vector resolution is used to resolve vector quantities using cosine or sine of adjacent angles; vector quantities obey the triangle laws. The cross product is the product of two or more vector quantities.

Here’s a video that sums it up:

What is The Difference between Scalar and Vector?

Points of Comparison Vector Scalar
Definition A quantity that has a direction and a magnitude. A quantity that has only a magnitude.
Types of Dimensions Vector can have one-dimensional, two-dimensional, or three-dimensional. Scalar has only one-dimensional.
Changes  Vector changes when their direction or magnitude is changed. Scalar changes when their magnitude only has changed.
Resolution Scalar quantities have the same value regardless of their direction, so they cannot be resolved. Using the cosine or sine of adjacent angles, you can resolve vector quantities in any direction.
Operations When a scalar and a vector operation are together, they will result in a vector quantity; however, when two or more scalar quantities are carried together, they will result in a scalar quantity. When two or more vector and scalar quantities are carried together, the result could be either a vector or a scalar quantity. For example, the product of vectors in subtraction or addition will result in vector quantity (cross-product); meanwhile, when mathematical operations are carried out between two vectors, the product can be vector or scalar.
Symbols Simple alphabets are used to express a scalar quantity such as V for velocity. Bold letters are used to express vector quantities, and over the letter, an arrow is put, for example, for velocity.
Calculations Simple Complex

What Is an Electric Current?

Electric current is defined as a movement of carries of electric charge, for example, protons carrying a positive charge and electrons carrying a negative charge; these particles are called sub-atomic particles. Another example of sub-atomic particles is atoms but not ordinary atoms, the excited atoms.

When atoms lose or gain an electron, it gains energy that excites it; this makes the atom’s electrons move from their levels to higher or lower levels. All these examples are considered images or examples of electric current. Electric current is defined as the electrons that carry the charge inside the wire when it comes to wires.

The current can be calculated by the amount of the value of the electric charge passing through a unit area of the wire in time. Current has two types, direct and alternating; the direct current has a constant direction; meanwhile, the alternating current alters its direction with time.

Conclusion

To sum up, electric current does have a direction and a magnitude; however, it’s a scalar quantity, not a vector quantity. The electric current doesn’t obey the law of the parallelogram law of vector and the triangle law of vector. The direction and magnitude are not the only factors determining if the quantity is a vector or a scalar.

Suppose the vector laws can be applied to a physical quantity, such as the parallelogram law of vector and the triangle law of vector. In that case, the physical quantity is a vector quantity. If the quantity doesn’t obey these laws, it’s a scalar quantity. Since the result of the summation of any two currents will be calculated using the algebraic sum. 

Then, the electric current is not a vector quantity regardless that it has a direction and a magnitude. Scalar quantities have many other examples, such as mass, length, speed, and duration. Meanwhile, examples of vector quantities are force, displacement, weight, and velocity.

Don`t copy text!
Scroll to Top