Electrostatics Question 701
Question: The insulation property of air breaks down when the electric field is $ 3\times 10^{6}V{{m}^{-1}}. $ The maximum charge that can be given to a sphere of diameter 5 m is approximately
Options:
A) $ 2\times {{10}^{-2}}C $
B) $ 2\times {{10}^{-3}}C $
C) $ 2\times {{10}^{-4}}C $
D) $ 2\times {{10}^{-5}}C $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ E=\frac{kQ}{r^{2}}\Rightarrow Q=\frac{E\times r^{2}}{k}=\frac{3\times 10^{6}\times {{( 2.5 )}^{2}}}{9\times 10^{9}} $
$ =2\times {{10}^{-3}}C $
