Suppose you left a 100-W light bulb on continuously for one month. If the electricity generation and transmission efficiency is 30%, how much chemical energy (in joules) was wasted at the power plant for this oversight? If the fuel consumption for one meal in Cambodia using a kerosene wick stove is 6 MJ (1 MJ = 1,000,000 joules), how many equivalent meals could be cooked with this wasted energy.

a

b

Explanation:

From the question we are told that

The power rating of the bulb is P = 100 W

The duration is t = 1 month = 1 * 30 * 24 = 720 h

The efficiency is

The fuel consumption for one meal is

Generally the energy consumed by the bulb is mathematically represented as

=>

=>

Generally the energy generated at the power plant that was wasted by the bulb is mathematically represented as

=>

=>

Converting this value  to  Joules

Generally the number of means that would be cooked is

=>    

photocells convert light energy to electricity