Household energy consumption calculation

• Definition: Electric power is the rate at which electrical energy is consumed or dissipated in an electrical circuit ($P = \frac{E}{t} = VI$).
• SI Unit: Watt (W).

1. Daily energy calculation:

• Heater: $P_1 = 1.5\text{ kW}$, $t_1 = 4\text{ h} \implies E_1 = 1.5 \times 4 = 6\text{ kWh/day}$
• Microwave: $P_2 = 1.5\text{ kW}$, $t_2 = 3\text{ h} \implies E_2 = 1.5 \times 3 = 4.5\text{ kWh/day}$
• Total daily energy = $6 + 4.5 = 10.5\text{ kWh/day}$

2. Monthly energy (30 days): $E_{\text{month}} = 10.5 \times 30 = 315\text{ kWh}$

3. Energy in Joules: $1\text{ kWh} = 3.6 \times 10^6\text{ J}$ $E_{\text{month}} = 315 \times 3.6 \times 10^6 = 1.134 \times 10^9\text{ J}$

Total units consumed = $315\text{ kWh}$ (units). Cost per unit = ₹ 7. $\text{Total Cost} = 315 \times 7 = \text{₹ } 2205$