A bulb is rated at 150 watt, converting 8\% energy into light. If energy of one photon is 4.42 × 10^ -19 J, how many photons are emitted by the bulb per second ?

Correct answer: A. 2.71 × 10^ 19 Power of the bulb, P = 150 W Energy converted into light per second, E = 8\% of 150 J E = (8)/(100) × 150 = 12 J Energy of one photon, E_p = 4.42 × 10^ -19 J Number of photons emitted per second, n = (E)/(E_p) n = 12 4.42 × 10^ -19 n = 2.71 × 10^ 19 Answer: 2.71 × 10^ 19

NEET 2026

Exam: NEET
Year: 2026
Subject: Chemistry
Chapter: Structure of Atom

NEET 2026 · Chemistry · Structure of Atom

A bulb is rated at 150 watt, converting 8\% energy into light. If...

A bulb is rated at

150

watt, converting

8\%

energy into light. If energy of one photon is

4.42 \times 10^{-19}

J, how many photons are emitted by the bulb per second ?

Options

A $2.71 \times 10^{19}$
B $3.06 \times 10^{19}$
C $27.2 \times 10^{19}$
D $1.35 \times 10^{19}$

Correct answer

A. $2.71 \times 10^{19}$

Step-by-step solution

Power of the bulb,

P = 150

W

Energy converted into light per second,

E = 8\%

150

E = \dfrac{8}{100} \times 150 = 12

J

Energy of one photon,

E_p = 4.42 \times 10^{-19}

J

Number of photons emitted per second,

n = \dfrac{E}{E_p}

n = \dfrac{12}{4.42 \times 10^{-19}}

n = 2.71 \times 10^{19}

Answer:

2.71 \times 10^{19}

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