Physics 10 Class Notes CHAPTER NO.13 ELECTROSTATICS
Class x Physics Note text and PDF download full chapter number 13 electrostatics. Physics Notes for X short and long question, Comprehensive Question, Assignment, Excessive, Numerical Problems & conceptual question.
Production of electric charges
Electroscope and its uses
Electric field and electric field intensity
Electric field lines
Capacitors and capacitance
Combination methods of capacitors.
Types and uses of capacitors
Solution of problems
Q1. Define electrostatics and electric charge? How objects can be electrified? Describe with the help of experiments?
Electrostatics is composed of two words, Electro and statics, Electro mean charge and static mean rest. So it is defined as,the branch of physics which deal with the study of charges at rest is called electrostatics.
The deficiency (or) excess of electrons on an object is called electric charge.
If there is excess of electrons on an object, then the object is called negatively charged. If there is deficiency of electrons on an object, then the object is called positively charged.
The properties of electric charge can be understood with the help of different experiments discussed as fellows.
Take glass rod and rub it with silk cloth, we will observe that the glass rod will attract small pieces of paper toward itself.
Similarly the same type of behavior is observed by the silk cloth. If we suspend glass rod and bring the silk cloth near it, they will attract each other.
Take a rubber rod and rub it with woolen cloth, again we observe that the rubber rod and woolen cloth, attract small pieces of paper toward itself. If we suspend the rubber rod and bring the woolen cloth near it, they will attract each other,
Before these experiments we observe that both the rods and both the cloths did not have this property of attraction. Since gravitational force is also attractive in nature. But the property of attraction in these two experiments is not due to gravitational force because gravitational force was present before rubbing of rods with the cloths but it was not strong enough to attract clothes toward the rods. The attraction is due to ‘electrical force between the charges placed on rods by cloths due to rubbing.
Suspend glass rod rubbed with silk cloth and bring another glass rod rubbed with silk cloth near to the first glass rod. We will observe that these glass rods repel each other, Now suspend rubber rod rubbed with woolen cloth and bring a glass rod rubbed with silk cloth near to it, we will observe that these Two rods attract each other, By bribing rubber rod rubbed with woolen cloth to the suspended rubber rod, we well observe that they also repel each other as shown in figure.
Q 2: Define conductor and insulator. Give examples?
The substances through which electric current can flow easily are called conductors.
In a metallic substances such as solid copper, iron, aluminum etc. the valance electrons are not bound to any particular nucleus. They can move freely. They are called free electrons. Those substances which have a large number of free electrons per unit volume can easily conduct electric current are known as good conductors.
The substances through which electric current cannot flow easily are called insulators.
Dry wood, plastic. glass. rubber etc.
In insulators the valance electrons are tightly bounded with the respective nucleus. Therefore, electric current cannot flow easily through insulator.