Formulas for electricity.

#### Force on a moving charge in a magnetic field

• Given by:
(1)
\begin{align} F = qvb\sin{\theta} \end{align}
• Note that $\theta$ is the angle between the particle's direction of movement and the magnetic field lines.
• Direction of the force is given by the Right hand palm rule, where I is given by the direction of the particle
• Note that, if it is an electron, the thumb points in the opposite direction.
• Be aware of the following:

#### Electric fields

• Electric field strength is given by
(2)
\begin{align} E_f =\frac{V}{d} \end{align}
• Note that it is the same between the metal plates, no matter the position in between them.
• Do not get this confused with Energy, which is why it's written as $E_f$ here instead.
• The force on a charged particle in this field is given by:
(3)
$$F = q E_f$$
• Note that the direction of this force is given by the charge of the particle.
• A negative charge would move towards the positive and away from the negative.
• A positive charge would move towards the negative and away from the positive.
page revision: 0, last edited: 01 Nov 2011 10:56