The motor effect common mistakes

Common mistakes

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Fleming's left-hand rule (HT only), then explain how it links to a student comparing motor and generator effects and the objective to recall and apply the equation F = B x I x l for a conductor at right angles to a magnetic field.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Fleming's left-hand rule (HT only), then explain how it links to a calculation using primary and secondary coils and the objective to identify force F in newtons, magnetic flux density B in tesla, current I in amperes and length l in metres.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Fleming's left-hand rule (HT only), then explain how it links to a bar magnet and plotting compass practical and the objective to rearrange F = B x I x l to calculate magnetic flux density, current or length where appropriate.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Fleming's left-hand rule (HT only), then explain how it links to a steel core electromagnet demonstration and the objective to apply MS 3b and MS 3c when using the motor-effect equation.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Fleming's left-hand rule (HT only), then explain how it links to a current-carrying wire between magnetic poles and the objective to recognise that the motor-effect equation is given on the Physics equation sheet.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Electric motors (HT only), then explain how it links to a loudspeaker coil moving in a magnetic field and the objective to state that a coil of wire carrying a current in a magnetic field tends to rotate.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Electric motors (HT only), then explain how it links to an alternator producing an AC output trace and the objective to describe rotation of a current-carrying coil in a magnetic field as the basis of an electric motor.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Electric motors (HT only), then explain how it links to a dynamo producing a DC output trace and the objective to explain how the force on a conductor in a magnetic field causes rotation of the coil in an electric motor.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Electric motors (HT only), then explain how it links to a moving-coil microphone investigation and the objective to link opposite forces on the sides of a current-carrying coil to the turning effect in an electric motor.

• motor-effect force direction: avoid motors and generators

  Treating motors and generators as interchangeable when answering about motor-effect force direction.

  Fix itInstead, identify the exact Unit 4.7 idea in Electric motors (HT only), then explain how it links to a step-up transformer on the National Grid and the objective to use motor-effect reasoning to explain the operation of a simple electric motor.