Assuming that a 25 watt bulb emits monochromatic yellow light of wavelength 0.57 μ. The rate of emission of quanta per second will be:

Question

Assuming that a 25 watt bulb emits monochromatic yellow light of wavelength 0.57 μ. The rate of emission of quanta per second will be: (A) 5.89 × 1015 s -1 (B) 7.28 × 1017 s -1 (C) 5 × 1010 s -1 (D) 7.18 × 1019 s -1

Tardigrade Admin · Accepted Answer

Let n quanta are evolved per second n[(h c/λ)]=25 J / s n (6.626 × 10-34 × 3 × 108/0.57 × 10-6)=25 n=7.18 × 1019 s-1

Q. Assuming that a $25$ watt bulb emits monochromatic yellow light of wavelength $0.57 μ$ . The rate of emission of quanta per second will be:

$5.89 \times 1 0^{15} s^{- 1}$

$7.28 \times 1 0^{17} s^{- 1}$

$5 \times 1 0^{10} s^{- 1}$

$7.18 \times 1 0^{19} s^{- 1}$

Let $n$ quanta are evolved per second

$n [\frac{h c}{λ}] = 25 J / s$

$n \frac{6.626 \times 1 0 ^{- 34} \times 3 \times 1 0 ^{8}}{0.57 \times 1 0 ^{- 6}} = 25$

$n = 7.18 \times 1 0^{19} s^{- 1}$

Q. Assuming that a 25 watt bulb emits monochromatic yellow light of wavelength 0.57μ. The rate of emission of quanta per second will be:

5.89×1015s−1

7.28×1017s−1

5×1010s−1

7.18×1019s−1