Question.
Which uses more energy, a $250 \mathrm{~W}$ TV set in $1 \mathrm{~h}$, or a $1200 \mathrm{~W}$ toaster in 10 minutes ?
Which uses more energy, a $250 \mathrm{~W}$ TV set in $1 \mathrm{~h}$, or a $1200 \mathrm{~W}$ toaster in 10 minutes ?
solution:
Energy used by $250 \mathrm{~W}$ TV set in $1 \mathrm{~h}=250 \times 1=250 \mathrm{Wh}$
Energy used by $1200 \mathrm{~W}$ toaster in $10 \mathrm{~min}$. (i.e., $1 / 6 \mathrm{~h})=1200 \times(1 / 6)=200 \mathrm{Wh}$
Thus, a $250 \mathrm{~W}$ TV set uses more energy in $1 \mathrm{~h}$ than a $1200 \mathrm{~W}$ toaster in 10 minutes.
Energy used by $250 \mathrm{~W}$ TV set in $1 \mathrm{~h}=250 \times 1=250 \mathrm{Wh}$
Energy used by $1200 \mathrm{~W}$ toaster in $10 \mathrm{~min}$. (i.e., $1 / 6 \mathrm{~h})=1200 \times(1 / 6)=200 \mathrm{Wh}$
Thus, a $250 \mathrm{~W}$ TV set uses more energy in $1 \mathrm{~h}$ than a $1200 \mathrm{~W}$ toaster in 10 minutes.
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