Defining Electric Charge
Electric charge is the basic physical property of matter that causes it to experience a force when kept in an electric or magnetic field. An electric charge is associated with an electric field and the moving electric charge generates a magnetic field. Combination of electric and magnetic fields is known as the electromagnetic field. Interaction of the charges generates an electromagnetic force which is the foundation of Physics.
The two types of electric charges are: Positive and Negative, commonly carried by charge carriers protons and electrons. Examples of the types of charges are subatomic particles or the particles of matter:
- protons are positively charged
- electrons are negatively charged
- neutrons have zero charge
The definition of electric charge is given as follows:
“Electric Charge is the property of subatomic particles that causes it to experience a force when placed in an electromagnetic field.”
Is Electric Charge a Vector Quantity?
Electric charge is a scalar quantity. Apart from having a magnitude and direction, a quantity to be termed a vector should also obey the laws of vector addition such as triangle law of vector addition and parallelogram law of vector addition, only then the quantity is said to be a vector quantity. In the case of an electric current, when two currents meet at a junction, the resultant current of these will be an algebraic sum and not the vector sum. Therefore, an electric current is a scalar quantity although it possesses magnitude and direction.
Measuring Electric charge
The electric charge is measured using coulomb.
“One coulomb is the quantity of charge transferred in one second.”
Mathematically, the definition of a coloumb is represented as:
Q = I.t
In the equation, Q is the electric charge, I is the electric current and t is the time.
Overview of Electric Charge
Electric Charge is the property of subatomic particles that causes it to experience a force when placed in an electromagnetic field.
Q = I.t
Properties of Electric Charge
Various properties of charge include the following:
- Additivity of Electric Charge
- Conservation of Electric Charge
- Quantization of Electric Charge
In any isolated system, Electric charge is conserved, which means the net electric charge of the system is constant. The algebraic sum of the fundamental charges in any isolated system remains the same.
To understand the properties of charge in detail, read the article below:
Types of electric charge
Two kinds of electric charges are there
- positive(+) charge
- negative(-) charge
When an object has a negative charge it means that it has more electrons than protons.
When an object has a positive charge it means that it has more protons than electrons.
When there is an identical number of positive and negative charges, the negative and positive charges would cancel out each other and the object would become neutral.
We might already know that like charges repel each other and unlike charges attract each other. But have you taken a minute to wonder how strong are these forces? Coloumb’s Law provides a means to calculate the strength of the force between two points.
Coloumb’s Law states that
The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.
The Coloumb’s Law is given by the expression:
where Fe is the electric force, q1 and q2 are electric charges, k is the Coloumb’s constant 8.988×109 N⋅m2/C2 and r is the distance of separation.
Methods of Charging
The process of supplying the electric charge to an object or losing the electric charge from an object is called charging.
An uncharged object can be charged in three different ways as follows:
- Charging by friction ( triboelectric charging)
- Charging by conduction
- Charging by induction
Charging by Friction
When two objects are rubbed against each other, charge transfer takes place. One of the objects loses electrons while the other object gains electrons. The object that loses electrons becomes positively charged and the object that gains electrons becomes negatively charged. Both the objects get charged due to friction and this method of charging is commonly known as electrification by friction.
Charging by Conduction
The method of charging an uncharged object by bringing it close to a charged object is known as charging by conduction. The charged conductor has an unequal number of protons and electrons, hence when an uncharged conductor is brought near it, it discharges electrons to stabilise itself.
Charging by Induction
The process of charging an uncharged conductor by bringing it near a charged conductor without any physical contact is known as charging by induction.
Charging By Conduction
Charging By Induction
Hope you have learnt about electric charge, its properties, formula along with terms and units.
Frequently Asked Questions – FAQs
How are electric charges distributed within the atom?
Why is an electric charge a scalar quantity?
When will an electric charge be negative?
When will an electric charge be positive?
What is the unit for measuring electric charge?
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