Which description correctly explains the left-hand rule?

Which description correctly explains the left-hand rule?

• A. If you grasp a wire with your left hand with your thumb pointing in the direction of electron current flow, your fingers wrap around the wire in the direction of the magnetic field.
• B. If you grasp with your left hand and point the thumb along the magnetic field, the fingers indicate current direction.
• C. The right-hand rule applies to electron current.
• D. The left-hand rule is unrelated to current direction.

Answer: (A)

Fleming’s left-hand rule shows how current, magnetic field, and force on a conductor relate. For electron flow, you use the left hand with the thumb pointing in the direction of the electron current. Then the fingers wrap around the wire in the direction of the magnetic field produced by that current. This works because magnetic field lines encircle a current-carrying wire, and reversing the current (electrons vs. conventional current) reverses the field direction, which is naturally captured by using the left hand for electron flow. So this description matches how the left-hand rule links the current direction to the surrounding magnetic field around the conductor. The other statements either mix up which part maps to which direction, rely on the right-hand rule inappropriately, or claim there’s no relation to current, which isn’t correct.

Fleming’s left-hand rule shows how current, magnetic field, and force on a conductor relate. For electron flow, you use the left hand with the thumb pointing in the direction of the electron current. Then the fingers wrap around the wire in the direction of the magnetic field produced by that current. This works because magnetic field lines encircle a current-carrying wire, and reversing the current (electrons vs. conventional current) reverses the field direction, which is naturally captured by using the left hand for electron flow.

So this description matches how the left-hand rule links the current direction to the surrounding magnetic field around the conductor. The other statements either mix up which part maps to which direction, rely on the right-hand rule inappropriately, or claim there’s no relation to current, which isn’t correct.