2. Rank the following in the order of how much of a corona discharge they would produce; from highest to least (e.g., if D is highest, then A, C, and B are lowest. entering DACB). Explain your response.
a. a large round metal ball hooked to a high voltage battery
b. a sharp metal needle connected by a wire to the ground (I. e. at zero voltage)
c. a large round metal ball hooked to a low voltage battery
d. a metal needle hooked to a high voltage battery
To rank the given items in terms of how much corona discharge they would produce, we need to consider a few factors that influence corona discharge.
Corona discharge occurs when an electric field at the surface of a conductor becomes strong enough to ionize the surrounding air or gas. The intensity of corona discharge is influenced by the following factors:
1. Voltage: Higher voltages lead to stronger electric fields, increasing the likelihood of corona discharge.
2. Shape of the conductor: Conductor shape affects the distribution of electric field lines. Edges and sharp points on a conductor create regions of high electric field intensity, making corona discharge more likely.
3. Radius of the conductor: The radius of the conductor determines the distance over which the electric field acts. A larger radius reduces the intensity of the electric field, decreasing the chance of corona discharge.
4. Grounding: Grounding refers to connecting a conductor to the earth, which maintains the conductor at a zero voltage potential.
Let's analyze each given item based on these factors:
a. A large round metal ball hooked to a high voltage battery:
- This setup involves a rounded shape, reducing the intensity of the electric field and making corona discharge less likely.
- However, a high voltage battery increases the electric field intensity, which could contribute to corona discharge.
b. A sharp metal needle connected by a wire to the ground (at zero voltage):
- The sharp needle shape increases the electric field intensity at its tip, making corona discharge more likely.
- Since the needle is connected to the ground, there will be no potential difference to create a significant electric field.
c. A large round metal ball hooked to a low voltage battery:
- Similar to situation 'a,' the rounded shape of the ball reduces the intensity of the electric field, making corona discharge less likely.
- Additionally, the low voltage battery significantly decreases the electric field intensity, further reducing the chance of corona discharge.
d. A metal needle hooked to a high voltage battery:
- Similar to situation 'b,' the sharp needle shape increases the electric field intensity at its tip, making corona discharge more likely.
- The high voltage battery contributes to a high electric field intensity, increasing the likelihood of corona discharge.
Based on the analysis, we can rank the given items from highest to least corona discharge as follows:
1. d (a metal needle hooked to a high voltage battery)
2. b (a sharp metal needle connected by a wire to the ground)
3. a (a large round metal ball hooked to a high voltage battery)
4. c (a large round metal ball hooked to a low voltage battery)
Keep in mind that the ranking is subjective, and the intensity of corona discharge can also be influenced by other factors like temperature and humidity.