Question

❤️ hey mate ❤️

solve this question **

i can spend rs 8.00 per month (30days) on electric light .if power is 20 paise per kWh and i use 5 identical bulbs for 5 hours a day, what should be the power of each bulb ?

Answer 1

solution :-

given in question .


Total cost = Rs 8.00 .

cost of each unit ( 1 kWh ) = 20 paise.

in rupees = Rs 0.20 .


total number of bulbs = 5

time for which bulbs run daily 5 hr.

Number of days = 30

in question we find power ( p ) = ?

let the power of each bulb = p

Total power = 5 × p ( since all bulbs are identical )

Number of units which I can use =

$\frac{total \: cost}{rate} \\ \\ = \frac{8.00}{0.20} = 40$
I can use 40 units of energy .

number of hours = 40 × 5 = 200 hr

power {p) =
$\frac{no \: of \: killowat \: hrs}{no \: of \: hours} \\ \\ \frac{30 \times 1000}{200} watts \\ \\ p \: = 150watts$

therefore each bulb =
$\frac{150}{5} \\ \\ = 30w$


I can use 5 bulbs of 30 watts each.


be brainly.