# Dot Product vs Cross Product

**Created: 05/11/2020**

**Last Updated: 05/16/2020**

**Introduction**

DOT product and Cross product are important to quantify 3-D geometric depended relationship of electrical circuit effects.

**Overview**

DOT product: output is the multiplicative product of effective parallel components of two vectors.

- Example vectors can be voltage waves along a transmission path such as straight copper trace. When the wave is propagate perfectly along the transmission path. We can predict the wave magnitude along each x position of the transmission by dot product the wave function and the distance function.

Cross product: output is the is the multiplicative product of effective perpendicular components of two vectors.

- Example: Lorentz force
- Two vector quantities are the
**current**(I) guided by a**wire**(L) and the**magnetic field**(B) produced by a strong magnet.- Note: a vector contains both a magnitude and direction, in the above case current is the magnitude and direction is guided by wire.

- Resultant force on the current carrying wire is the Cross product of current vector and magnetic field vector
- F= I*L X B

- Two vector quantities are the