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1.
A van der Graaf generator is used in classroom demonstrations to illustrate the production
of large electric fields with visible arcs. The threshold field for air to reach dielectric breakdown is
3*10^6 V/m.
In a particular demo, the van der Graaf dome is a hollow sphere of 25 cm radius that was discharged before the demo. At t=0, the charge-carrying belt is set to rotate at constant
speed so that 0.6*10^-6 C are put at the center of the dome every second. How long should it roughly take for an electric arc to form with an object held nearby?
(a) 15 s
(b) 35 s
(c) 50 s
(d) 120 s
(e) 250 s
2. 3*10^6=Voltage across gap/size of the gap
3. What I did was take 3 million and multiply by .25m. This gave me a value of 750,000 volts which is what is required for a spark to be made at that distance correct?
Now what i don't understand is how i would go from coulombs to volts with the given information
A van der Graaf generator is used in classroom demonstrations to illustrate the production
of large electric fields with visible arcs. The threshold field for air to reach dielectric breakdown is
3*10^6 V/m.
In a particular demo, the van der Graaf dome is a hollow sphere of 25 cm radius that was discharged before the demo. At t=0, the charge-carrying belt is set to rotate at constant
speed so that 0.6*10^-6 C are put at the center of the dome every second. How long should it roughly take for an electric arc to form with an object held nearby?
(a) 15 s
(b) 35 s
(c) 50 s
(d) 120 s
(e) 250 s
2. 3*10^6=Voltage across gap/size of the gap
3. What I did was take 3 million and multiply by .25m. This gave me a value of 750,000 volts which is what is required for a spark to be made at that distance correct?
Now what i don't understand is how i would go from coulombs to volts with the given information