Read the following passage and answer the accompanying questions - Leaving Cert Physics - Question 11 (b) - 2005

In an electric motor, electrical energy is converted into kinetic energy. The electrical energy supplied to the motor is transformed into movement, allowing the motor to perform mechanical work.

The commutator in a dc motor serves to ensure that the current always flows in the same direction through the coil. This allows for continuous rotation by reversing the connections of the coil to the power source every half turn.

The output voltage from an ac generator is typically sinusoidal. The sketch would illustrate a graph with 'time' on the x-axis and 'varying (voltage)' on the y-axis, showing the sinusoidal wave pattern.

The slip rings are connected to brushes made of carbon or metal, which maintain electrical contact with the rotating slip rings. This connection allows the alternating current produced in the generator to flow into the external circuit.

A transformer operates on the principle of electromagnetic induction between two coils; it typically steps up or steps down the voltage. An induction coil, however, uses a primary coil to induce a high voltage in a secondary coil, and is often used to create high-voltage pulses.

The Irish physicist who invented the induction coil is Dr. Nicholas Callan.

1. Core losses: These include hysteresis losses and eddy current losses in the core material.
2. Winding resistance losses: The resistance in the transformer windings leads to energy loss in the form of heat.