Q: What is the difference between cal and kcal?
A calorie (cal) is energy to heat 1g water by 1°C. A kilocalorie (kcal) = 1,000 cal. Food labels show "Calories" which are actually kilocalories. "200 Calories" on food = 200 kcal = 836,800 joules.
Q: How many kWh does a home use per day?
An average Indian household uses 3–8 kWh per day. An AC uses about 1–2 kWh/hour. A 100W bulb for 10 hours = 1 kWh. Electricity bills in India are charged per kWh (unit).