Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
Newton per coulomb (N/C) is a unit that measures the strength of an electric field. It represents the force exerted on a unit positive charge placed in an electric field, quantifying the intensity of the electric field at that point.
5 Must Know Facts For Your Next Test
The newton per coulomb (N/C) is the SI unit for the strength of an electric field, representing the force per unit charge.
Electric fields are vector quantities, meaning they have both magnitude and direction. The newton per coulomb unit captures the magnitude of the electric field.
The direction of the electric field is determined by the direction of the force experienced by a positive test charge placed in the field.
The strength of an electric field is inversely proportional to the square of the distance from the source charge, as described by Coulomb's law.
The electric flux through a surface is calculated by integrating the electric field over that surface, with the units of the flux being Nโ m^2/C.
Review Questions
Explain how the newton per coulomb unit is used to quantify the strength of an electric field.
The newton per coulomb (N/C) unit represents the force per unit charge experienced by a small positive test charge placed in an electric field. It directly measures the intensity or strength of the electric field at that point. The magnitude of the electric field in N/C is equal to the force in newtons that would be exerted on a charge of 1 coulomb placed at that point in the field. This allows the electric field to be quantified and compared across different locations or systems.
Describe how Coulomb's law relates to the concept of electric field strength measured in newton per coulomb.
Coulomb's law states that the electrostatic force between two point charges is inversely proportional to the square of the distance between them. This inverse square relationship also applies to the electric field strength, as measured in newton per coulomb. The farther away from a charged object, the weaker the electric field strength becomes, following an inverse square dependence. The newton per coulomb unit captures this distance-dependent behavior of the electric field, allowing the field intensity to be quantified and compared at different points in space around a charged object.
Explain how the concept of electric flux is connected to the newton per coulomb unit for electric field strength.
Electric flux is a measure of the total electric field passing through a given surface, calculated by integrating the electric field over that surface. The units of electric flux are Nโ m^2/C, which can be expressed as the product of newtons per coulomb (the electric field strength) and square meters (the area of the surface). This relationship demonstrates how the newton per coulomb unit for electric field strength is a fundamental component in determining the electric flux, which is a crucial concept in understanding the behavior of electric fields and their interactions with surfaces and volumes in space.
The region surrounding an electric charge where a test charge would experience an electric force. The electric field is defined as the force per unit charge experienced by a small positive test charge placed at that point.
The physical law that states the electrostatic force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.