Hi, In this question, you are asked \"What minimum radius must alarge conducting
ID: 1676168 • Letter: H
Question
Hi, In this question, you are asked "What minimum radius must alarge conducting sphere of an electrostatic generating machine haveif it is o be at 35,000 V without discharge into the air?" Iunderstand that r = V / E, and that I substitute 35,000 V forthe "V" value. However, the answer shows substitution of 3E6 V/mfor the "E" value. I am unsure as to where this value comes from.Any help would be greatly appreciated. Thanks! Hi, In this question, you are asked "What minimum radius must alarge conducting sphere of an electrostatic generating machine haveif it is o be at 35,000 V without discharge into the air?" Iunderstand that r = V / E, and that I substitute 35,000 V forthe "V" value. However, the answer shows substitution of 3E6 V/mfor the "E" value. I am unsure as to where this value comes from.Any help would be greatly appreciated. Thanks!Explanation / Answer
we can regard the sphere as a spherical capacitor havingcapacitance of C C=40R V=Q/C E=k*Q/R2=V/R=>R=V/E E=3*106 V/m, which is limitted electric fieldbreakdown in air, R=0.0117 m R=0.0117 m