Download - Charging by Contact 2: CONDUCTION
![Page 1: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/1.jpg)
Charging by Contact 2:CONDUCTION
![Page 2: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/2.jpg)
• Name two ways that objects can receive an electric charge.
• Describe how a material can be charged by contact (conduction).
KEY WORDSConduction Pith ball
Charge separation Electroscope
Particle model for electrostatics
![Page 3: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/3.jpg)
Because of the ability of electrons to move, it is possible to induce a charge separation in objects.
This works better for some materials (conductors)than others (insulators).
Charge separation is deliberate movement of electrons to one part of a material.
It is responsible for most attraction forces seen in objects.
![Page 4: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/4.jpg)
Electrons move - causes charge separation.
Attraction
![Page 5: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/5.jpg)
Electroscope is a tool for determining whether or not an electrical charge is present in an object.
It can provide 3 kinds of measurement:
• detect the presence of an electrostatic charge.• determine the type of charge on an object.• determine the amount of charge on an object.
We will use two kinds: pith ball electroscopes and foil electroscopes (Pith is a light plant material).
![Page 6: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/6.jpg)
![Page 7: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/7.jpg)
Charged object moves away – electrons redistribute - leaves fall back down.
![Page 8: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/8.jpg)
2. Conduction• Electric charge can travel by touching a charged object to a neutral object.• Results in a neutral object gaining a charge.
Electrons move towards the more positive object - imparting charge.
1. Triboelectric Charging• Two neutral objects are rubbed together, which
transfers electrons resulting in charged objects.
![Page 9: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/9.jpg)
4. Charge transferred to pith - same as rod. (repulsion)
1. Charged rod.
2. Charge separation in pith ball (attraction)
3. Pith touches rod – electrons move towards positives.
e-
Negative charge (excess e-)
Negative charge (excess e-)
CONDUCTION – with (-) rod
![Page 10: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/10.jpg)
4. Charge transferred to pith - same as rod. (repulsion)
1. Charged rod.
2. Charge separation in pith ball (attraction)
3. Pith touches rod – electrons move towards positives.
e-
Positive charge (lost e-)
Positive charge (lost e-)
CONDUCTION – with (+) rod
![Page 11: Charging by Contact 2: CONDUCTION](https://reader038.vdocuments.us/reader038/viewer/2022103006/56813e93550346895da8df3c/html5/thumbnails/11.jpg)
Particle model of electrostatics:• Charge is a particle that is conserved – can’t be created or destroyed.
• Two kinds of charge - positive and negative / attraction and repulsion.
• Neutral objects have equal numbers of positive and negative charges.
• Only negative charges move.
• Two neutral objects can be charged by rubbing (friction) against each other – triboelectric charging.
• Charged object can charge neutral object by touching – conduction.
• Materials, which allow charges to move easily, are called conductors. Materials in which charges do not move easily are called insulators