QUESTION 2 2.1 Name the correct rating for circuil breakers used in the following subcircuiks: 2.1.1 Light subcircuit 2.12 Stove subcircuit 2.1.3 Geyser subcircuit \( (3 \times 1) \) 2.2 Explain the operating principle of an immersion thermostat commonly found in geysers. 2.3 Draw the wiring diagıam of a geyset subcircuit

Below is one acceptable answer. Note that actual equipment ratings may vary with local wiring rules and the exact appliance ratings, but many standard domestic installations use the following: ───────────────────────────── 2.1 Circuit Breaker Ratings • Light Subcircuit: A 6‑amp miniature circuit breaker is normally used. (Some local standards may permit a 10‑amp breaker if the circuit load is higher, but 6 A is typical for lighting.) • Stove Subcircuit: Because a full electric stove (or cooktop) usually draws several kilowatts (for example, a 7.2 kW appliance at 230 V draws around 31 A), a dedicated circuit protected by a 40‑amp breaker is quite common. (For a smaller or “modular” stove the rating may differ; however, heavy loaded cooktop installations normally use a 40 A circuit.) • Geyser Subcircuit: A typical electric geyser (water heater) rated at around 3 kW draws roughly 13 A at 230 V. For such a load a 20‑amp breaker is usually employed. ───────────────────────────── 2.2 Operating Principle of an Immersion Thermostat An immersion thermostat is a temperature‐sensing and control device mounted inside the geyser so that it is in direct contact with the water. Its operation is usually based on one of the following principles:  • A bimetallic strip or a thermo‐sensitive element expands as the water temperature rises. When the water reaches a preset temperature, the bending (or change in resistance, if a thermistor is used) causes a pair of electrical contacts within the thermostat to separate (open). This breaks the circuit and cuts power to the heating element.  • Some designs include two functions: a “running” thermostat that cycles the heater on and off at the desired temperature and a “cut‐out” which acts as a safety device to permanently disconnect the heater if the water temperature exceeds a dangerous value. In short, when the water is cool the thermostat’s contacts close to allow current to power the heater; once the preset temperature is reached the contacts open to stop further heating. ───────────────────────────── 2.3 Wiring Diagram of a Geyser Subcircuit Below is an illustrative wiring diagram in schematic form: [Mains Supply] L N E │ │ │ │ │ │ ┌┴┐ ┌┴┐ ┌┴┐ │ │ │ │ │ │ │CB│ ←– Circuit Breaker (20 A for geyser) │ │ │ │ │ │ └┬┘ └┬┘ └┬┘ │ │ │ ├──────────── Isolation Switch (Double-Pole) │ │ │ │ │ │ └─────────────┴─────────────┘ │ ▼ [Immersion Thermostat] (Sensing & switching) │ ▼ [Geyser Heating Element] │ └────────────│ │ Return to Neutral (N) (Protective Earth (E) is connected to the geyser’s casing) ───────────────────────────── Explanation: 1. The live (L) mains conductor first passes through a circuit breaker (here rated at 20 A for the geyser circuit). 2. Next, a double‐pole isolation (or disconnect) switch is provided so that the geyser can be isolated for servicing. 3. The switched live then feeds the immersion thermostat, whose contacts control whether power is applied to the heating element. 4. The heating element is connected in series with the thermostat. When the thermostat closes (below the set temperature), power flows and heats the water. 5. The neutral (N) completes the circuit. 6. The protective earth (E) is connected to all accessible metal parts for safety. This diagram (which can be drawn by hand or with software) illustrates the typical arrangement for a dedicated geyser circuit. ───────────────────────────── Note: Always consult and follow the latest local electrical wiring standards and regulations when working on domestic wiring installations.