A lightbulb has an efficiency of 1.8%. How much heat energy (not light energy) is generated by the bulb every second if the bulb has a power of 120 W?

A. 2.16 J

B. 5.98 J

C. 117.8 J

D. 1.22 J

Question

A lightbulb has an efficiency of 1.8%. How much heat energy (not light energy) is generated by the bulb every second if the bulb has a power of 120 W?

A. 2.16 J

B. 5.98 J

C. 117.8 J

D. 1.22 J

ivancsc1996 · Answer

Well since the purpose of the bulb is to produce light then the efficiency of heat production is 98.2% so:$$Q=\frac{ 100-1.8 }{ 100 }120W1s=117.8J$$