At which location on the line joining two equal positive (like) point charges is the net electric field intensity equal to zero?
At the midpoint between the charges
Each positive charge produces a field directed away from itself, with magnitude \(E = \frac{kq}{r^2}\).
Between the two charges these fields point in opposite directions, so a null point is possible there.
For equal charges, the magnitudes are equal where the distances are equal: \(\frac{kq}{x^2} = \frac{kq}{(d - x)^2} \Rightarrow x = \frac{d}{2}\).
So the net field is zero at the midpoint. A point closer to one charge has the nearer charge’s field dominating; far away the fields add (both point outward along the line) and only tend to zero at infinity; at a charge’s own location its field is undefined (infinite).
Hence, the answer is At the midpoint between the charges.
Similar Questions
Which property of a test system does NOT influence the intrinsic electric field vector created by a stationary source charge at a given observation point?
For two equal positive point charges, what is the direction of the individual electric field components created by each charge in the region between them?
A point charge of 2 µC is placed 0.5 m away from another point charge in air. What is the magnitude of the electric field intensity at this point?
An electric field of 100 N/C points to the right. What is the electric force on a +2 C charge placed in this field?
Important Questions from Electric Fields and Gauss' Law
The surface charge density of a thin spherical shell placed in an air medium is 88.54 c/m2 The intensity of the electric field measured 12 mm outside the shell from the centre of the shell is 5.625 × 101 2 N/C. The thin spherical shell has a radius of:
The electric flux passing through a surface of area A = 8j m2 in an electric field vector E = 2i + 3j - 4k V/m (bold is for vectors) is:
- Let a total charge $2Q$ be distributed in a sphere of radius $R$, with the charge density given by $\rho(r) = Cr^2$, where $r$ is the distance from the centre. Two charges $A$ and $B$, of $-Q$ each, are placed on diametrically opposite points, at equal distance, '$a$' from the centre. If $A$ and $B$ do not experience any force, then:
- Two point charges $q_1 \left( {\sqrt {10} {\rm{\mu C}}} \right)$ and $q_2(-18\sqrt{2} {\rm{\mu C}})$ are placed on the x-axis at $x = 0$ m and $x = 4$ m respectively. The electric field (in V/m) at a point $(1, 3)$ m is,
$\left[ {{\rm{Take\;}}\frac{1}{{4{\rm{\pi }}{\epsilon_0}}} = 9 \times {{10}^9}{\rm{N}}{{\rm{m}}^2}{{\rm{C}}^{ - 2}}} \right]$ The electric field between the two plates of a parallel plate (area = 5.0 × 10-2m2) capacitor is given by E = (2.0 × 105 – 4.0 × 104 t) V/m where t is in second. What is the magnitude of the displacement current between the plates? (ε0 = 8.85 × 10-12 F/m)
