Question

16 bulbs of 40 watts are used for 6 hours a day along with 1 bulb of 100 watts for 2 hours. calculate the units of energy consumed in 30 days also calculate the electrical bill for a month. if the cost per unit is rupees 11

Answer 1

Cost = 1333.2[rupees]

Step-by-step explanation:

We can solve this problem by using unit analysis of quantities, in this way we have:

16 [bulbs] * 40 [watts] = 640 [watts]

1 [bulb] * 100 [watts] = 100 [watts]

Now for each power and its time of working.

`640[w]*(6 hr)/(1day) * 30 [days] = 115200 [w-hr]\\100[w]*(2hr)/(1day) * 30[days] = 6000 [w-hr]`

115200 [w*hr] = 115.2[Kw-hr]

6000 [w*hr] = 6[kw-hr]

If the cost is 11 rupees/1[kw-hr], then we have

115.2 + 6 = 121.2 [kw-hr]

Cost = 121.2 [kw-hr] * 11 rupees/1 [kw-hr]

Cost = 1333.2 [rupees]