A $40\,\text{W}$ lamp loses $34\,\text{J}$ of energy each second as heat to its surroundings. What efficiency does the lamp have?
- A$0.15\%$
- B$15\%$
- C$18\%$
- D$85\%$
Physics 0625 · IGCSE · Energy, work and power
A $40\,\text{W}$ lamp loses $34\,\text{J}$ of energy each second as heat to its surroundings. What efficiency does the lamp have?