Calculating Magnetic Force Flashcards

All 6 cards in this deck

What is the equation for the force on a current-carrying conductor at right angles to a magnetic field?

$F = B \times I \times l$ (force in N = magnetic flux density in T × current in A × length in m).

What are the units of magnetic flux density?

Tesla (T), also written as newton per ampere metre (N/A m).

What are the steps to calculate the current in a wire from the force on it?

e.g. $F = 0.06$ N, $B = 0.2$ T, $l = 0.5$ m

1. Write $F = B \times I \times l$.
2. Rearrange: $I = \dfrac{F}{B \times l}$.
3. Substitute: $I = \dfrac{0.06}{0.2 \times 0.5} = 0.6$ A.

Before using $F = B \times I \times l$, what must a length given in millimetres be converted to?

Metres.

e.g. $30$ mm $= 0.03$ m.

True or false? In $F = B \times I \times l$, $l$ is the total length of the wire.

False. It is only the length of wire inside the magnetic field.

For which orientation of the wire does the equation $F = B \times I \times l$ apply?

When the conductor is at right angles (perpendicular) to the magnetic field.