Question

an electric bulb of 100watt is used for for 12 hours in a day calculate the unit of energy consumed in the month of April also convert the energy per day in joule, if 1 unit of energy cause rs3what is the bill for the month of April

Answer 1

Dear Student,

Energy consumed per day in Joules = $$\begin{gathered} \frac{100}{1000}\mathrm{KW}\times 12=1.2{\mathrm{Js}}^{-1} \\ \Rightarrow 1.2\times 3.6\times {10}^6\mathrm{J}=4.32\times {10}^6\mathrm{J}=4.32\mathrm{MJ} \end{gathered}$$

Unit of Energy consumed per day = $\frac{100}{1000}\mathrm{KW}\times 12=1.2\mathrm{KWh}$

Units of energy consumed in month of April (30 days) = $1.2\times 30=36\mathrm{KWh}$

cost of 1 unit = 3 Rs
cost of 36 units = 36 $\times$ 3 = 108 Rs

Regards