Question

An electric dipole consists of a positive charge and negative charge of magnitude $4 \mu C$ each placed at a distance of $5 mm$. What is the dipole moment?

• A. $2 \times 10^{-6} C - m$
• B. $2 \times 10^{-8} C - m$
• C. $4 \times 10^{-5} C - m$
• D. $5 \times 10^{-8} C - m$

Answer 1

Answer: (B)

$q=\pm 4 \mu c$
$2 a=5 \times 10^{-3} m$
$|\vec{P}|=q \times 2 a$
$=4 \times 10^{-6} \times 5 \times 10^{-3}$
$=20 \times 10^{-9}$
$|\vec{ P }|=2 \times 10^{-8} cm$