Force on a Current-Carrying Conductor in a Magnetic Field

Contents / notes

• Quantitative treatment of force between two parallel current-carrying conductors.
• Force on a charge moving in a magnetic field.
• The direct-current (DC) motor.
• Electromagnets.
• Carbon microphone.
• Moving-coil and moving-iron instruments.
• Conversion of galvanometers to ammeters and voltmeters using shunts and multipliers.
• Sensitivity of a galvanometer.

Candidate objectives

• Determine the direction of force on a current-carrying conductor using Fleming's left-hand rule.
• Interpret attractive and repulsive forces between two parallel current-carrying conductors using diagrams.
• Determine the relationship between force, magnetic field strength, velocity and the angle at which a charge enters the field.
• Interpret the working of a DC motor.
• Analyse the principles of electromagnets and give examples of their applications.
• Compare moving-iron and moving-coil instruments.
• Convert a galvanometer into an ammeter or voltmeter.
• Identify factors affecting the sensitivity of a galvanometer.