Please help. Big confusion about potential. Urgent.?
My book said the dome of a van de Graff generator had a very high potential. However if the dome is negatively charged, shouldn't it be very low potential?
Potential is defined as the epe per test charge at a certain point.
And when we don't know the distance between a test charge and the dome, what is meant by "potential of the dome."
Is it referring to the surface potential of the dome?
- 天同Lv 74 年前最愛解答
The word "high" here carries a relative concept. It means a "high potential difference relative to ground". Should the dome carry large amount of -ve charges, the potential difference of it would still be high in respect to earth potential."
If an object carries charges, it will acquire a certain potential from the charges. At the same time, the charged object will also raise (or lower, if the charges are -ve) the potential of the surrounding space.
That said, charges accumulated on the dome of a van de Graff generator cause the dome to acquire a certain potential.
In terms of the definition of potential, the "potential of the charged dome (assume the charges are +ve)" is the work done required to bring a (+ve) unit test charge from infinity to reach the dome.
- astonLv 53 年前
yes, you correct. but it is normal positively charged