Answer:
a) 0.3 m
b) r = 0.45 m
Step-by-step explanation:
given,
q₁ = 0.44 n C and q₂ = 11.0 n C
assume the distance be r from q₁ where the electric field is zero.
distance of point from q₂ be equal to 1.8 -r
now,
E₁ = E₂



1.8 = 6 r
r = 0.3 m
b) zero when one charge is negative.
let us assume q₁ be negative so, distance from q₁ be r
from charge q₂ the distance of the point be 1.8 +r
now,
E₁ = E₂



1.8 =4 r
r = 0.45 m