Question

Conceptual Questions:

1. Does two charged objects require contact for an electrical force to be exerted on the other charged object?

2. What equation can we use to relate the electric field to electrical force? Describe the variables of the equation.

3. When there is only a positive charge in the electric field, what is the direction for the electric field and what is the direction for the electric force, in relation to the charge?

4. When there is only a negative charge in the electric field, what is the direction for the electric field and what is the direction for the electric force, in relation to the charge?

Answer 1

EXPLANATION OF THE FIRST QUESTION:

No, two charged objects do not require contact for an electrical force to be exerted on the other object, because the electrical force is a non-contact force. In nature, one charge object can pull or push other charged objects without touching them. so, the electric force is a non-contact force.
For example, if we take a plastic comb and rub it in our dry hair for about one minute and then bring it to a tiny piece of paper, this comb attracts the pieces of paper. The tiny pieces of paper move towards the comb and stick to it. This happens because when a plastic comb is rubbed in dry hair, it gets electrically charged by friction. Therefore it exerts an electrostatic force of attraction on the pieces of paper. Due to this force, the tiny pieces of paper stick to the comb. In this example, we can see that the comb does not touch the tiny pieces of paper to attract them. So, without contact, the tiny pieces of paper get stick to the comb by the electrostatic attraction force. Therefore, we can say that the electrostatic force is a non- contacting force.

In nature, there are two types of charge object. They are positive and negative. Like charge ( positive- positive or negative- negative) repulse each other, and opposite charge ( positive-negative or negative-positive) attract each other without touching each other.

EXPLANATION OF THE SECOND QUESTION:

The relation of the electric field with electric force is

where E = electric field.
F = electric force generated by a charge Q.
q = electric charge which experiences electrostatic force created by another charge Q. This charge (q) also called test charge.

EXPLANATION OF THE THIRD QUESTION:

The concept is the electric field lines always directed away from the positive charge and directed towards the negative charge.

In the first case,
There are two possibilities. One, when an electric field is generated by a positive charge (+Q) and in this field, there is a positive change (+q), then field lines of two charges always directed away from each other for both charges. So, they repel each other. The direction of force is away from both charges.
Secondly, when the electric field is generated by a negative charge (-Q) and in this field, there is a positive charge (+q), then the electric field lines directed from the positive charge to negative charge. The electrostatic force is attractive, and here negative charge attracts the positive charge.

In the second case,
There are two possibilities. One, when an electric field is generated by a negative charge (-Q) and in this field, there is a negative change (-q), then field lines of two charges always directed towards each other for both charges. So, they repel each other. The direction of force is towards both charges.
Secondly, when the electric field is generated by a positive charge (+Q) and in this field, there is a negative charge (-q), then the electric field lines directed from the positive charge to negative charge. The electrostatic force is attractive, and here positive charge attracts the negative charge.