What is a Charge?
It is to be noted that the bodies which are charged bodies in a system of charges that are very small as compared to the distance which is between them are treated as point charges. Very often we deal with systems where the influence of many systems is taken into consideration. To calculate the final effect in such cases that we need to subtract and add these charges from one another.
To simplify the operations which are involved, it is very necessary that we study the properties of charges which are point. In this topic and section we will learn about three such point properties of charges, the electric charge additivity of the charge, the electric charge conservation and at the quantization of charge which is electric charge.
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Conservation of Electric Charge
If we look at the principle of conservation of charges we can notice that the charges are neither destroyed nor created, they are transferred from one body to the other body as well. If we take an example of two objects one has some charge and the other one has no charge which are made to come in contact with each other.
The transfer of charge is from the object which is possessing some charge to the other object which is possessing no charge until and the charge is equally distributed over the whole system as well.
Here if we see so we can notice that no charge is lost or created and is only transferred from the one which is possessing an excess of charge to the other possessing.
Electric Charge
An Electric charge can be defined as it is the physical property of matter that can experience a force when it is placed in an electromagnetic field. There are basically two types of electric charge that are negative and positive that are commonly carried by electrons and protons respectively.
The like charges are the charges which repel each other and unlike charges are the charges which attract each other. An object that is having an absence of charges which are net is referred to as neutral charges. The very early knowledge of how the substances which are charged interact is now called classical electrodynamics and still accurate for problems which really do not require consideration of effects of quantum.
An Electric charge is said to be a conserved property, the net charge which is of an isolated system, the amount of charge which is positive charge minus the amount of charge which is negative charge cannot change. Electric charge can be carried out by particles which are subatomic.
If there are electrons which are more than protons in a piece of matter, then it will have a negative charge for sure and if there are fewer it will have a positive charge. And if there are an equal number of the charges then it will be neutral. Then it is said that the Charge is quantized.
It comes in multiple which are integer of individual that have small units which are called the elementary charge that is e and about 1.602×10−19 coulombs is its value that is considered as the smallest charge which freely exist that is the particles called quarks have smaller charges that are multiples of ⅓ e.
But they are only found in combination and one more point here is that they are always combined to form particles with integer charge. The proton has a charge of positive that is +e and the electron has a charge of negative which is −e.
Overview of the Topic
The fundamental property Charge of forms or of matter that exhibit replushion or electrostatic attraction in the presence of other matter. The electric charges which are is a characteristic property of many subatomic particles. The free standing charges of particles are integer multiples of the elementary charge that is e, we can say that electric charge value is quantized.
Scientist Michael Faraday in his electrolysis experiments was the first man to specifically note the nature of the discrete electric charge. Physicist Robert Millikan's who did the oil drop experiment demonstrated this fact directly and along with that he measured the elementary charge.
It has been discovered that one type of particles that are quicks and that have fractional charges of either −1/3 or +2/3
but. it is duly believed that they always occur in multiples of integral charge which can also be said as free-standing quarks that have never been observed.
By the process of convection we can notice that the charge of an electron is negative, that is denoted by −e, while that of a proton is positive that is denoted by +e. The particles which are Charged particles whose charges have the same sign repel one another.
And particles whose charges have always been different signs are the ones which attract. The law of Coulomb's quantifies the force of electrostatic which is between two particles by asserting that the force is directly proportional to the product of their charges, and that is inversely proportional to the square of the distance which is between them. The antiparticle charge is equal to that of the corresponding particle but along with opposite signs.
Units
The SI or we can also call it as the derived unit of quantity of electric charge is the coulomb that is denoted by the symbol: C. In the particle which is of modern practice, we can observe that the phrase "amount of charge" is used instead of "quantity of charge". The symbols which are lowercase symbols that are q are often used to denote a quantity of electricity or charge. The charge of amount 1 electron is an elementary charge which is defined as a fundamental constant in the SI units system.
FAQs on Basic Properties Electrical Charge
1. What is an electric charge and what are its types?
An electric charge is the fundamental physical property of matter that causes it to experience a force when placed in an electromagnetic field. It is an intrinsic property of elementary particles like electrons and protons. There are two types of electric charges:
- Positive Charge: The charge carried by a proton.
- Negative Charge: The charge carried by an electron.
Objects with like charges (positive-positive or negative-negative) repel each other, while objects with unlike charges (positive-negative) attract each other.
2. What are the three fundamental properties of electric charge?
The three fundamental properties of electric charge are:
- Additivity of Charge: The total charge of a system is the algebraic sum of all the individual charges present in the system. For example, if a system contains two charges, +2q and -5q, the total charge is +2q - 5q = -3q.
- Conservation of Charge: The total electric charge in an isolated system remains constant. Charge can neither be created nor destroyed; it can only be transferred from one body to another.
- Quantization of Charge: The electric charge on any object is an integral multiple of the elementary charge, 'e'. The formula is q = ne, where 'q' is the total charge, 'n' is an integer (n = 0, ±1, ±2, ...), and e = 1.602 × 10⁻¹⁹ Coulombs.
3. What is the principle of conservation of electric charge?
The principle of conservation of electric charge states that for an isolated system (a system from which charge cannot enter or leave), the net electric charge remains constant over time. This means that charge can be moved from one object to another within the system, but the total amount of positive charge minus the total amount of negative charge does not change. For instance, when a glass rod is rubbed with silk, electrons are transferred from the rod to the silk, making the rod positively charged and the silk equally negatively charged, but the total charge of the rod-silk system remains zero.
4. How is the additive property of charge different from the addition of mass?
The additive property of charge differs from the addition of mass in a crucial way. While both are scalar quantities and can be added, electric charge can be positive or negative. Therefore, the total charge is an algebraic sum, where signs are considered. For example, a system with +5C and -2C has a net charge of +3C. In contrast, mass is always a positive quantity. The total mass of a system is always the simple arithmetic sum of individual masses and can never be zero or negative by adding more mass.
5. Can a body have a charge of 2.4 x 10⁻¹⁹ C? Explain why or why not based on the quantization principle.
No, a body cannot have a charge of 2.4 x 10⁻¹⁹ C. This is due to the quantization of electric charge, which states that any charge (q) must be an integral multiple of the elementary charge (e ≈ 1.6 x 10⁻¹⁹ C).
To check, we use the formula q = ne, where 'n' must be an integer.
n = q / e
n = (2.4 x 10⁻¹⁹ C) / (1.6 x 10⁻¹⁹ C)
n = 1.5
Since 'n' is 1.5, which is not an integer, a charge of this magnitude is not possible. Charge can only exist in discrete packets of 'e', such as 1e, 2e, -3e, etc.
6. How does the law of conservation of charge hold true during processes like pair production and annihilation?
The law of conservation of charge is a fundamental principle that holds true even in high-energy physics phenomena:
- Pair Production: In this process, a high-energy photon (which is electrically neutral, charge = 0) converts into an electron-positron pair near a nucleus. The electron has a charge of -e, and the positron has a charge of +e. The total charge of the products is (-e) + (+e) = 0. Thus, the charge before (0) and after (0) is conserved.
- Annihilation: This is the reverse process where an electron (-e) and a positron (+e) collide and annihilate each other, producing two or more photons (charge = 0). The total charge before the collision is (-e) + (+e) = 0, and the total charge after is also 0, again conserving the net charge.
7. If charge is conserved, how do objects become charged by rubbing or induction?
The conservation of charge applies to an isolated system. When objects become charged, no new charge is created. Instead, existing charges are simply redistributed.
- Charging by Rubbing (Friction): When you rub a glass rod with a silk cloth, electrons are transferred from the rod to the silk. The rod becomes positively charged, and the silk becomes equally negatively charged. The total charge of the rod-silk system remains zero, thus conserving charge.
- Charging by Induction: When a charged rod is brought near a neutral conductor, it causes a separation of charges within the conductor. If the conductor is then grounded, charge flows between the conductor and the Earth. The net charge of the rod-conductor-Earth system remains constant throughout the process. The conductor is left with a net charge only by moving charge to or from the vast reservoir of the Earth.
