Question

Four +2 μC charges are placed at the positions (10 cm, 0 cm), (−10 cm, 0 cm), (0 cm, 10 cm), and (0 cm, −10 cm) such that they form a diamond shape centered on the origin. A charge of +5 μC is placed at the origin. If the force between a +2 μC and a +5 μC charge separated by 10 cm has a magnitude of 9 N, which of the following can we say about the force on the +5 μC charge at the origin in this case?Four 2 charges are placed at the positions (10 , 0 ), (10 , 0 ), (0 , 10 ), and (0 , 10 ) such that they form a diamond shape centered on the origin. A charge of 5 is placed at the origin. If the force between a 2 and a 5 charge separated by 10 has a magnitude of 9 , which of the following can we say about the force on the 5 charge at the origin in this case?a. The force on the charge at the origin is 18 N.b. The force on the charge at the origin is 36 N.c. The force on the charge at the origin is 0.d. The force on the charge at the origin is 9 N.

Answer 1

Answer:

c. The force on the charge at the origin is 0

Explanation:

We know by Coulomb's law:

Force between to two charges (here repulsive since both are +ve) sperated by distance 'r' in space is:

$F = \frac{1}{4\pi \epsilon_0} \frac{Q_1.Q_2}{r^2}$

where:

$\epsilon_0$= permittivity of free space

$Q_1, Q_2$ being the charges

In this case the product $Q_1\times Q_2$ remains constant and also the distance "r" is constant which yields the force identical in each case.

Since identical charges are kept at all the four corners of a diamond shape and are equidistant from the origin where another charge of +5 μC is kept, all the charges from the vertices will apply  equal repulsive force on the charge at origin cancelling out the force vectors which yields the force to be zero.