Three equal charges are at three of the corners of a square of side d. A fourth charge of equal magnitude is at the center of the square as shown in Figure above. Which of the arrows shown represents the net force acting on the charge at the center of the square?

An electron traveling along the +x-axis enters an electric field that is directed vertically down, i.e., along the negative y-axis. What will be the direction of the electric force acting on the electron after entering the electric field?

What is the main difference between electrical and gravitational forces?

By what method will a positively charged rod produce a negative charge on a conducting sphere that is placed on an insulating surface?

A charged rod carrying a negative charge is brought near two spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres?

When the magnitude of two interacting charges is increased by a factor of 2, the electrical forces between these charges is __________.