Question

16 bulbs of 40 W are used for 6 hour a day along with one 100 W bulb for 2 hours. Calculate the units of energy consumed in one day by all the bulbs.

Answer 1

P = W/t

16 bulbs of 40W makes =16×40= 640W

So in 6 hrs the energy consumed is = 640×6×3600 = 13824000 

$\frac{13824000}{ 10^{6} *3.6}$ = 3.84 KWh

A 100 W bulb for 2 hrs will consume energy = 100×2×3600 =

200×3600/3.6×10^6 = 0.2 KWh

so total energy consumed = 3.84 + 0.2 = 4.04 KWh = 4.04 units 

Answer 2

P = W/t

16 bulbs of 40W makes =16×40= 640W

So in 6 hrs the energy consumed is = 640×6×3600 = 13824000 

 = 3.84 KWh

A 100 W bulb for 2 hrs will consume energy = 100×2×3600 = 

200×3600/3.6×10^6 = 0.2 KWh

so total energy consumed = 3.84 + 0.2 = 4.04 KWh = 4.04 units