Question

The "dielectric strength" is the electric field magnitude at which a substance begins to spark. Air begins to conduct or spark when the electric field is about 3 million N/C. How does this electric field compare to the magnitude of the electric field in an atom

Answer 1

To solve this problem we will use two given concepts. The electric field in an atom and the electric field in the air. The first is a theoretical case whose value will be brought up while the second is given by the statement. We will divide the values and compare the proportion to obtain the respective conclusions. The electric field in an atom is

$E = 5.75*10^{11}n/c$

Dialectic strength of air is given as

$E_d = 3*10^6 N/C$

Hence the electric field in an atom cannot be less than the dialectic field strenth of air

Divide E and $E_d$, we have

$\frac{E}{E_d} = \frac{5.75*10^{11}}{3*10^6}$

$E = (1.91*10^5)e_D$

Thus the electric field of an atom is within and order of $10^5$ the dialectic strength of air instead of factor $10^{10}$

Therefore the electric field in an atom is greater than the dialectic field strenth of air