Electrostatics Question 818
Question: In a Van de Graff generator, a spherical metal shell is to be $ 15\times 10^{6}V $ electrode. The dielectric strength of the gas surrounding the electrode is $ 15\times {{10}^{-7}}V{{m}^{-1}}. $ The minimum radius of the spherical shell required is
Options:
A) 1m
B) 2m
C) 1.5m
D) 3m
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Here, $ V=15\times 10^{6}V $
dielectric strength $ =5\times 10^{7}V{{m}^{-1}} $
Maximum electric field, E = 10% of dielectric strength
As $ E=\frac{V}{r}\text{ }\therefore r=\frac{V}{E}=\frac{15\times 10^{6}}{5\times 10^{6}}=3m $
