Question:medium
A 250 W electric bulb of 80% efficiency emits a light of 6626 \AA wavelength. The number of photons emitted per second by the lamp is ($h = 6.626 \times 10^{-34}$ Js)
A 250 W electric bulb of 80% efficiency emits a light of 6626 \AA wavelength. The number of photons emitted per second by the lamp is ($h = 6.626 \times 10^{-34}$ Js)
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When the wavelength is given in Angstroms ($X$ \AA), and Planck's constant is given as $6.626$, look for numerical cancellations! Here, $6626$ and $6.626$ simplify the math significantly.
Updated On: May 6, 2026
- $1.42 \times 10^{17}$
- $2.18 \times 10^{16}$
- $6.66 \times 10^{20}$
- $2.83 \times 10^{16}$
- $4.25 \times 10^{16}$
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The Correct Option is C
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