Q17Basic Electrical Engineering

Electrical energy ($E$) is the total amount of electrical work done over a period of time. While the standard SI unit of energy is the Joule (Watt-second), electricity boards commercially bill consumers based on the Board of Trade (BOT) unit, which is the kilowatt-hour (kWh).

Example Calculation: Consider a household using the following appliances daily: 1. A $1500\text{W}$ ($1.5\text{kW}$) Geyser operated for $2\text{ hours}$. 2. Four $50\text{W}$ Fans ($200\text{W}$ total, or $0.2\text{kW}$) operated for $10\text{ hours}$. Energy consumed by Geyser: $1.5\text{kW}\times 2\text{h}=3.0\text{ kWh (Units)}$ Energy consumed by Fans: $0.2\text{kW}\times 10\text{h}=2.0\text{ kWh (Units)}$ Total Daily Consumption: $3.0+2.0=5.0\text{ Units}$. If the electricity tariff is ₹$8.00$ per unit, the daily cost is $5.0\times 8=\text{₹}40$.