Magnetic Field Direction: Right-Hand Thumb Rule Quiz and Flashcards

Questions and Answers

Determining the direction of magnetic field lines around a current-carrying conductor

In the direction of the magnetic field lines

Clockwise in a plane perpendicular to the wire

<p>The concentric circles representing the magnetic field around it become larger and larger</p> Signup and view all the answers

<p>Because the field due to each turn adds up and the current in each circular turn has the same direction</p> Signup and view all the answers

Study Notes

A convenient way to find the direction of magnetic field associated with a current-carrying conductor is given by the Right-Hand Thumb Rule.

Connect a copper wire vertically between two points X and Y in series with a battery, a plug, and a key.
Sprinkle iron filings uniformly on a cardboard and note the current through an ammeter.
Close the key to allow current to flow through the wire, keeping the copper wire straight.
Gently tap the cardboard to observe the pattern of iron filings.

The iron filings align themselves in a pattern of concentric circles around the copper wire.
These concentric circles represent the magnetic field lines.
The direction of the magnetic field can be found by placing a compass at a point over a circle and observing the direction of the needle.
The direction of the north pole of the compass needle gives the direction of the field lines produced by the electric current through the straight wire at that point.
The direction of magnetic field lines gets reversed if the direction of current through the straight copper wire is reversed.