Question

What was your electric potential relative to a metal pipe if a spark jumped 1.1 cm through dry air from your finger to the pipe?

_____V

Answer 1

The electric field is given by volts/distance:
`E= (V)/(d)`. The breakdown voltage of dry air is about 3x10^6V/m. So solving for V we get

`V=Ed`
or
`V=(3e6V/m)(0.011m)=33,000V`

Answer 2

Electric potential = V = 33 KV

Step-by-step explanation:

The breakdown is an electric stress phenomenon. The value of electric field at which breakdown of dry air occur is 3 × 10^6 V/m. So,

E = 3 × 10^6 V/m

d = 1.1 cm = 1.1 × 10^-2 m

We know that:

E = V/d

V = Ed

V = (3 × 10^6)( 1.1 × 10^-2)

V = 33000 V

V = 33 KV