Electric Charges and Electric Force

Which of the following statements is true regarding electric charges?

Four charges are placed at the corners of a square with side length $a$. Two charges are $+q$ and two are $-q$, arranged such that no two adjacent charges have the same sign. What is the electric field at the center of the square?

Three charges are arranged as follows: A charge $+q$ is at (0,0), a charge $-q$ is at (a,0), and a charge $+2q$ is at (a/2, a$\sqrt{3}$/2). What is the direction of the net electrostatic force on the charge at the origin?

Which of the following best describes the electric field?

Two point charges, $q_1 = +3 \mu C$ and $q_2 = -4 \mu C$, are separated by a distance of 3 m. What is the magnitude of the electrostatic force between them? (Assume $k = 9 \times 10^9 Nm^2/C^2$)

Two identical conducting spheres have charges of $+6q$ and $-2q$. They are brought into contact and then separated. What is the final charge on each sphere?

Two metal spheres of different sizes have initial charges. Sphere A has a charge of +5Q, and Sphere B has a charge of -3Q. The spheres are brought into contact and then separated. What is the final charge on each sphere?

A proton (charge +e) is released from rest in a uniform electric field E. Describe the subsequent motion of the proton.

A test charge of $+2 \mu C$ experiences a force of 0.04 N in a certain electric field. What is the magnitude of the electric field at the location of the test charge?

A charge of $+5 \mu C$ is placed in an electric field of 200 N/C. What is the magnitude of the electric force experienced by the charge?