What is the direction of the vector of electric dipole moment?

Options

A. From positive to negative
B. From negative to positive.
C. Unchanged.
D. Negative axis only.

Explanation

To determine the direction of the vector of an electric dipole moment, we can follow these steps:

### Step 1: Understand the Definition of Electric Dipole Moment
The electric dipole moment (\( \vec{p} \)) is defined as the product of the charge (\( Q \)) and the distance (\( d \)) between the two charges. Mathematically, it is expressed as:
\[ \vec{p} = Q \cdot \vec{d} \]
where \( \vec{d} \) is a vector pointing from the negative charge to the positive charge.

### Step 2: Identify the Charges
In an electric dipole, we have two charges: a positive charge (+Q) and a negative charge (-Q).

### Step 3: Determine the Direction of the Dipole Moment
The direction of the electric dipole moment vector is defined to be from the negative charge to the positive charge. Thus, if we denote the negative charge as -Q and the positive charge as +Q, the direction of the dipole moment vector is:
\[ \text{Direction of } \vec{p} = \text{from } -Q \text{ to } +Q \]

### Step 4: Relate to Electric Field Direction
The electric dipole moment vector aligns with the electric field created by the dipole. Therefore, when placed in an external electric field, the dipole moment tends to align itself in the direction of the electric field.

### Conclusion
Thus, the correct answer to the question regarding the direction of the vector of electric dipole moment is from the negative charge to the positive charge.

### Final Answer
The direction of the vector of electric dipole moment is from negative to positive charge.

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