Two positive charges of 6 �C are separated by a distance of 50 cm in air. What is the electric field strength at the midpoint of the line joining the charges?
Zero. The E-fields due to the two particles are equal and opposite at the midpoint. They cancel each other.
makes sense thanx!!
To determine the electric field strength at the midpoint of the line joining the charges, we can use the principle of superposition.
The electric field due to each charge at the midpoint will contribute to the total electric field at that point.
The electric field strength (E) due to a point charge (q) at a distance (r) can be calculated using the equation:
E = k * (q / r^2)
where k is Coulomb's constant, which is approximately equal to 9 x 10^9 Nm^2/C^2.
In this case, we have two positive charges of 6 μC each. So the total charge (Q) is 2 * 6 μC = 12 μC = 12 x 10^-6 C.
The distance between the charges is 50 cm, which is equal to 0.5 m. Since the midpoint is equidistant from both charges, the distances from the midpoint to each charge are also 0.5 m.
Now we can calculate the electric field due to each charge at the midpoint and then add them together to find the total electric field.
Electric field due to one charge:
E1 = k * (q / r^2) = (9 x 10^9 Nm^2/C^2) * (6 x 10^-6 C / (0.5 m)^2)
Note: the square of 0.5 m is used in the denominator because electric field decreases with the square of the distance.
E1 ≈ 4.32 x 10^4 N/C
Since the midpoint is equidistant from both charges, the electric field due to the second charge at the midpoint will be the same as the electric field due to the first charge.
So, the total electric field at the midpoint is given by the sum of the electric field due to each charge:
Etotal = 2 * E1 = 2 * 4.32 x 10^4 N/C = 8.64 x 10^4 N/C
Therefore, the electric field strength at the midpoint of the line joining the charges is 8.64 x 10^4 N/C.