Core Concepts (Target: 'S' Pass)

• State: What happens when a current-carrying wire is placed in a magnetic field?

• Identify: What rule helps determine the direction of the force in the situation above?

• Define: What is electromagnetic induction?

• Name: What device is used to change AC voltages from one value to another?

• Recall: Does a generator convert electrical energy to mechanical, or mechanical to electrical?

• List: Name the two main parts of a simple DC motor.

Understanding & Application (Target: 'C' Pass)

• Explain: What is the function of the split-ring commutator in a DC motor?

• Describe: How can you increase the strength of the electromotive force (voltage) induced in a coil of wire? (List two ways).

• Apply: Explain the difference between a step-up and a step-down transformer in terms of their coil structure.

• Explain: Why does a transformer not work with a DC supply?

• Differentiate: What is the key difference between Fleming's Left-Hand Rule and Fleming's Right-Hand Rule (i.e., when do you use each one)?

Analysis & Higher-Order Thinking (Target: 'B' / 'A' Pass)

• Analyse: Describe the energy conversions that occur in a bicycle dynamo to light up a bulb.

• Justify: An AC generator and a DC motor have very similar structures but perform opposite functions. Explain this statement.

• Calculate: A step-up transformer is used to change a 12 V AC supply to 240 V. If there are 100 turns on the primary coil, how many turns must the secondary coil have?

• Synthesize: Using Fleming's Left-Hand Rule, explain the forces on the sides of the coil in a simple DC motor that cause it to rotate.

O/L Exam Tip: Remember: The Left Hand Rule is for Motors (Force). The Right Hand Rule is for Generators (Induced Current). Practice using them. Transformer calculations using the turns/voltage ratio are also common.