Explanation: Given that a lightbulb has an efficiency of 13.1%.How much light energy (not heat energy) is generated by the bulb every second if the bulb has a power pf 8W?
The input power = 8W
The output power = ?
The efficiency = 13.1%
Using the formula below:
Efficiency = (power output / power input) × 100
13.1 = (Power output / 8 ) × 100
0.131 = power output / 8
Cross multiply to make the power output the subject of formula
Power output = 0.131 × 8
Power output = 1.048 W
Therefore, the light energy (not heat energy) generated by the bulb every second is 1.048 W
mantle convection is the very slow creeping motion of earths solid silicate mantle caused by convection currents carrying heat from the interior to the planet's surface.
