Question

The breakdown field for air is about $2\times {10}^6$ volt/m. Therefore, the maximum charge that can be placed on a sphere of diameter 10cm is

• A. $2.0\times {10}^{-4}$ C
• B. $5.6\times {10}^{-7}$ C
• C. $5.6\times {10}^{-2}$ C
• D. $2.0\times {10}^2$ C

Answer 1

The correct option is C $5.6\times {10}^{-2}$ C

The breakdown field for air $=2\times {10}^6$ Volt/m

diameter $=10\times {10}^{-2}m$

$E=q\times d$

or, $2\times {10}^6=q\times 10\times {10}^{-2}$

or, $q=5.6\times {10}^{-2}$