Flemings Left-hand Rule (ht Only) (GCSE Physics)

A motor’s coil side A experiences a force up and side B experiences a force down. What net effect does this produce on the coil according to Fleming’s left-hand rule?

A horizontal bar of length 0.40 m carries 10 A of current to the right in a magnetic field of 0.50 T directed into the page. What is the direction and magnitude of the force on the bar?

A student sets up a small DC motor and observes the coil side nearest them moves toward them. Using Fleming’s left-hand rule, which combination of field and current directions could explain that motion (assume conventional current direction shown)?

A moving-coil loudspeaker has a magnetic field from the permanent magnet directed left-to-right. If a positive current pulse flows from the front of the cone into the coil (front ? back), which initial direction does the coil (and cone) move?

Which finger in Fleming’s left-hand rule shows the direction of the magnetic field?

Which of the following best explains why reversing the direction of current in a motor coil reverses the rotation direction?

A straight conductor 0.50 m long lies perpendicular to a uniform magnetic field of 0.40 T. A steady current of 8.0 A flows in the conductor. What is the magnitude of the magnetic force on the conductor?

An electron beam (negative charges) moves to the right through a magnetic field pointing into the page. Using Fleming’s left-hand rule for conventional current, which way is the magnetic force on the electrons?

In a single-turn rectangular coil in a uniform downward magnetic field, the front face of the coil carries current left-to-right while the back face carries current right-to-left. Using Fleming’s left-hand rule, the front face experiences a force in which direction relative to the coil?

A conductor of length L carries current I through a region of magnetic flux density B at 90°. The magnitude of the force is given by F = BIL. Which of these changes increases F by a factor of 4?

In a small DC motor the commutator reverses contact so the coil current flips each half-turn. Using Fleming’s left-hand rule, why does the commutator reversing current at that moment keep rotation continuous rather than reversing it?