An immersion water heater is rated 2.0 kW. On a particular day it is switched on for 30 min.
a. (i) Calculate the electrical energy supplied to the water heater in joule.
b. (ii) Express the same energy in kilowatt-hour.
c. (iii) If the cost of electrical energy is ₹6.00 per kWh, determine the cost of operating the heater for that day.