Two bulbs ‘A’ and ‘B’ emit red light and yellow light at $8000 Å$ and $4000 Å$ respectively. The number of photons emitted by both the bulbs per second is the same. If the red bulb is labelled as $100$ watts, find the wattage of the yellow bulb.

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Solution

Let, $n$ be the no. of photons emitted by bulbs per second & $W$ be the wattage of yellow bulb.
Since, $Total energy = n \times Energy of one photon$
For red bulb, $100 = n \times \frac{12400}{8000} \times 1.6 \times 10^{- 19} . . . (i)$
For yellow bulb, $W = n \times \frac{12400}{4000} \times 1.6 \times 10^{- 19} . . . (i i)$

Since value of $n$ is same for both bulb, we can equate (i) and (ii).
$W = 200$ watts

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Two bulbs ‘A’ and ‘B’ emit red light and yellow light at 8000 Å and 4000 Å respectively. The number of photons emitted by both the bulbs per second is the same. If the red bulb is labelled as 100 watts, find the wattage of the yellow bulb.

Two bulbs ‘A’ and ‘B’ emit red light and yellow light at $8000 Å$ and $4000 Å$ respectively. The number of photons emitted by both the bulbs per second is the same. If the red bulb is labelled as $100$ watts, find the wattage of the yellow bulb.