The energy of light of frequency 2.0 x 10¹5}Hz is (h = 6.63 x 10^{-34}Js)

Correct Answer is : 1.33 x 10−18^{-18}−18J

Correct Answer is : 1.33 x 10−18^{-18}−18J

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JAMB Physics 2024 Paper

Question : 28

Total: 125

^{15}

^{-34}

Js)

Solution:

Concept:

Photon energy depends directly on the frequency of the electromagnetic wave.

The greater the frequency, the greater the energy carried by each photon.

Explanation:

Use the photon energy equation:

E = h f

Here,

h = 6.63 \times 10^{-34}\ \mathrm{J\cdot s}

is Planck's constant.

The frequency of the light is

f = 2.0 \times 10^{15}\ \mathrm{Hz}

Substitute the values into the formula:

E = (6.63 \times 10^{-34}) \times (2.0 \times 10^{15})\ \mathrm{J}

Multiply the coefficients and add the powers of ten:

E = 13.26 \times 10^{-19}\ \mathrm{J} = 1.326 \times 10^{-18}\ \mathrm{J}

Rounded to two significant figures, this becomes

1.33 \times 10^{-18}\ \mathrm{J}

Answer:

1.33 \times 10^{-18}\ \mathrm{J}

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