A special kind of light bulb emits monochromatic light of wavelength 630 nm. Electrical energy is supplied to it at the rate of 60 W, and the bulb is `93%` efficient at converting that energy to light energy. How many photons are emitted by the bulb during its lifetime of 730 h?

Explanation

To find the number of photons emitted by the light bulb during its lifetime, we can follow these steps:

### Step 1: Calculate the total energy supplied to the bulb
The power of the bulb is given as 60 W. The bulb operates for 730 hours. We first convert the time from hours to seconds:

\[ T = 730 \, \text{hours} \times 3600 \, \text{seconds/hour} = 2628000 \, \text{seconds} \]
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