Define electric dipole moment. Write its SI unit ?

Options

A. newton
B. coulomb
C. farad
D. debye

Answer

**Step-by-Step Solution:**

1. **Definition of Electric Dipole Moment:**
An electric dipole moment is defined as a vector quantity that represents the separation of positive and negative charges in a system. It is calculated as the product of the magnitude of one of the charges and the distance between the two charges.

Mathematically, it can be expressed as:
\[ \vec{p} = Q \cdot \vec{d} \]
where:
- \( \vec{p} \) is the electric dipole moment,
- \( Q \) is the magnitude of one of the charges (the same for both charges, +Q and -Q),
- \( \vec{d} \) is the vector pointing from the negative charge to the positive charge, and its magnitude is the distance \( L \) between the charges.

2. **Direction of Electric Dipole Moment:**
The direction of the electric dipole moment is defined from the negative charge to the positive charge.

3. **SI Unit of Electric Dipole Moment:**
The SI unit of electric dipole moment can be derived from its definition. Since it is the product of charge (in coulombs) and distance (in meters), the SI unit is:
\[ \text{Coulomb meter (C m)} \]

**Final Answer:**
The electric dipole moment is defined as the product of the magnitude of one of the charges and the distance between the two charges. Its SI unit is Coulomb meter (C m).

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