Aim: To find effects of charged bodies which have been rubbed by different materials.
Present this in the form of Aim, Apparatus, Procedure, Observations, Inference etc.
Answers
Answer:
When two different materials are rubbed together, there is a transfer of electrons from one material to the other material. This causes one object to become positively charged (the electron loser) and the other object to become negatively charged (the electron gainer).
Explanation:
Charging by induction using a negatively charged object
In this section, we shall learn about the transfer of charge by induction using a negatively charged object. Let us consider two metal spheres A and B touching each other, as shown in the figure. Let us take a negatively charged rubber balloon. If we bring the charged balloon near the spheres, electrons within the two-sphere system will be induced to move away from the balloon due to the repulsion between the electrons of the balloon and the spheres. Subsequently, the electrons from sphere A get transferred to sphere B.The migration of electrons causes the sphere A to become positively charged and the sphere B to be negatively charged. The overall two-sphere system is hence electrically neutral. The spheres are then separated using an insulating cover such as gloves or a stand as shown in the figure (avoiding direct contact with the metal)
When a negatively charged balloon is brought near the sphere system, the electrons in the sphere will be forced to move away due to repulsion. The migration of electrons causes sphere A to become completely positive and sphere B to become negative.
In this section, we shall learn about the transfer of charge through the process of induction using a positively charged object. Taking two spheres A and B, touching each other, as shown in the figure, if we bring a positively charged balloon near sphere A, the electrons from sphere B migrate towards sphere A due to the attraction between opposite charges, thus leaving the sphere B deficit of electrons. As a result, the sphere A is negatively charged and the sphere B is positively charged. The spheres are then separated using an insulating cover, a stand or gloves. When the balloon is removed, the charges in sphere A and B redistribute, spreading out evenly
When a positively charged balloon is brought near the sphere system, the electrons from sphere B will migrate towards sphere A due to the force of attraction. Now, sphere A is negatively charged and the sphere B is positively charged.
An electroscope is an instrument that is used to detect the presence and magnitude of electric charges on a body. An electroscope is commonly used by physics teachers to demonstrate the electrostatic principles of charging and charge interactions.
The demonstration of the induction process of charging is commonly performed with an electroscope. In this demonstration, a charged particle is brought close to but not touching the electroscope. The electrons in the electroscope are induced to move due to the presence of the charged particle above the plate of the electroscope. With the charged particle still held above the plate, the electroscope is touched. At this point, electrons will flow between the electroscope and the ground, giving the electroscope an overall charge. The needle of the electroscope deflects indicating an overall charge when the charged particle is pulled away from it. From this demonstration, the following fundamental principles can be summarised:
The object being charged by induction never touches the charged particle.
The charged object does not transfer electrons to or receive electrons from the object being charged.
The object being charged is touched by a ground; electrons are transferred between the ground and the object being charged (either into the object or out of it).
The charged object serves to polarize the object being charged.
The object being charged ultimately receives a charge that is opposite that of the charged object that is used to polarize it.
The application of inductive charging can be divided into high power and low power categories. The low power applications generally include handheld devices, phones, computer and other devices which charge at power levels below 100 watts. High power inductive charging applications include charging of batteries of power levels above 1 kilowatt. The most prominent application is the charging of electric vehicles where an automated and wireless inductive charging is provided as an alternative to plug-in charging.