Two spheres A and B are charged with the charges of +10 and +20 coulomb respectively and separated by a distance of 80 cm. The electric field at point on the line joining the centres of the two spheres will be zero at a distance from the sphere A :

Options

A. 45 cm
B. 33 cm
C. 60 cm
D. 20 cm

Answer

B

Explanation

`10/(4 p epsilon_(0)x^(2))=1/(4 pi epsilon_(0)) . (20xx1)/((0.8-x)^(2))`
`2x^(2)=(0.8-x)^(2)`
`1.414x=0.8-x,x=33cm`