Correct Answer - Zero ; `(1.2xx10^(12) q) NC^(-1)` towards the corner without charge
Length of each side `a = 0.1m = 10cm`
`:.` distance of the center of the cube from each corner,
`r = (a sqrt(3))/(2) = (10 sqrt(3))/(2) = 5 sqrt(3) cm`
`= 5 sqrt(3) xx10^(-2) m`.
When identical point charges `+q` each are at the eight corners of the cube, net field intensity at the center is zero (cancelling out in four pairs). When one of the corner charges is removed, three pairs of E values cancel. Due to charge on seventh corner,
`E = (1)/(4pi in_(0)) (q xx 1)/(r^(2)) = 9xx10^(9) (q)/((5 sqrt(3) xx10^(-2))^(2))`
`= (1.2xx10^(12)q) NC^(-1)`
It is towards the corner without charge directed radially away from `+q`.
