Welcome back — been a while! Let's pick up where you left off. First, let's calculate the total weekly electricity cost to address part (b). Step 1: Calculate daily energy consumption for each appliance. The formula for energy consumption is $E = P \times t$, where $E$ is energy in kilowatt-hours (kWh), $P$ is power in kilowatts (kW), and $t$ is time in hours (h). Cooker: Power $P = 2000 \text{ W} = 2 \text{ kW}$ Time $t = 3 \text{ hours/day}$ Daily energy $E_{\text{cooker}} = 2 \text{ kW} \times 3 \text{ h} = 6 \text{ kWh}$ Lights (10 lights): Power per light $= 40 \text{ W}$ Total power for lights $P = 10 \times 40 \text{ W} = 400 \text{ W} = 0.4 \text{ kW}$ Time $t = 6 \text{ hours/day}$ Daily energy $E_{\text{lights}} = 0.4 \text{ kW} \times 6 \text{ h} = 2.4 \text{ kWh}$ Water Heater: Power $P = 2400 \text{ W} = 2.4 \text{ kW}$ Time $t = 2 \text{ hours/day}$ Daily energy $E_{\text{heater}} = 2.4 \text{ kW} \times 2 \text{ h} = 4.8 \text{ kWh}$ Step 2: Calculate total daily energy consumption. $$ E_{\text{total daily}} = E_{\text{cooker}} + E_{\text{lights}} + E_{\text{heater}} $$ $$ E_{\text{total daily}} = 6 \text{ kWh} + 2.4 \text{ kWh} + 4.8 \text{ kWh} = 13.2 \text{ kWh} $$ Step 3: Calculate total weekly energy consumption. There are 7 days in a week. $$ E_{\text{total weekly}} = 13.2 \text{ kWh/day} \times 7 \text{ days/week} = 92.4 \text{ kWh} $$ Step 4: Calculate the total weekly electricity cost. The cost per unit (1 kWh) is ₦900. $$ \text{Total weekly cost} = E_{\text{total weekly}} \times \text{Cost per unit} $$ $$ \text{Total weekly cost} = 92.4 \text{ kWh} \times ₦900/\text{kWh} = ₦83,160 $$ Now, let's answer the specific questions: a) Explain why the electrician made the recommendations above. The electrician's recommendations are based on electrical safety and proper circuit design. • Disconnected from 240 V mains supply: This suggests that the appliance (likely the water heater or cooker) was either drawing excessive current for the existing wiring, causing an overload, or was connected improperly, posing a fire or shock hazard. High-power appliances require dedicated circuits with appropriate wiring and circuit breakers. • Discouraged connecting sockets in series: Household appliances are designed to be connected in parallel to the mains supply so that each receives the full supply voltage (240 V) and operates independently at its rated power. Connecting them in series would cause them to operate below their rated power (e.g., dim lights, slow heating) and is an incorrect and potentially unsafe wiring method. • Emphasized earthing: Earthing (grounding) is a critical safety feature. It provides a low-resistance path for fault current to flow directly to the ground in case a live wire accidentally touches the metal casing of an appliance. This causes the fuse to blow or the circuit breaker to trip, preventing electric shock. b) Determine if the amount budget for is sufficient. The owner's weekly budget is ₦70,000. The calculated total weekly electricity cost is ₦83,160. Since ₦83,160 > ₦70,000, the budget is ❌ not sufficient. c) Identify ways of reducing the electricity bill. To reduce the electricity bill, the household needs to reduce its total energy consumption. • Use energy-efficient appliances (e.g., LED lights instead of incandescent bulbs, energy-star rated appliances). • Reduce the usage time of high-power appliances like the cooker and water heater. • Switch off lights and appliances when they are not in use. • Utilize natural light during the day to reduce the need for artificial lighting. • Improve insulation for the water heater to reduce heat loss, thus requiring less energy to maintain water temperature. • Unplug chargers and appliances when not in use to avoid phantom load (standby power consumption). Send me the next one 📸