Physics 9702 · AS & A Level · Energy conservation

Energy conservation — practice question

The battery in a small tablet computer starts out uncharged. It is linked to a constant $10\,\text{W}$ power supply for $2.0$ hours in order to charge the battery. The charging process has an efficiency of $80\%$. What amount of energy is stored in the battery?

  • A$1.6 \times 10^1\,\text{J}$
  • B$1.6 \times 10^3\,\text{J}$
  • C$5.8 \times 10^4\,\text{J}$
  • D$5.8 \times 10^6\,\text{J}$

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