An LED consumes of electrical power

PHYSICS · Single correct · CBSE · Physics · Dual Nature of Radiation and Matter · Dual Nature of Radiation and Matter

Problem

An LED consumes

2.0\,\text{W}

of electrical power, but only

25\%

of that power is emitted as monochromatic blue light of wavelength

450\,\text{nm}

. If a camera shutter is open for

1/60\,\text{s}

, how many blue photons are emitted during the exposure? (a)

7.5\times10^{16}

(b)

1.1\times10^{18}

(c)

1.9\times10^{16}

(d)

5.7\times10^{16}