Question

Calculate the wavelength of each of the following frequencies of electromagnetic radiation.

1) 1045 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)

Express your answer using four significant figures.

2) 835.6 MHz (common frequency used for cell phone communication)

Express your answer using four significant figures.

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Calculate the energy of a photon of electromagnetic radiation at each of the following frequencies. (these answers do not depend on x10)

1)104.2 MHz (typical frequency for FM radio broadcasting)

Express your answer using four significant figures.

2)1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)

Express your answer using four significant figures.

3) 835.6 MHz (common frequency used for cell phone communication)

Express your answer using four significant figures.

Answer 1

(1) We know that wave length , = c /

Where

= frequency = 1045 kHz = 1045x10³ Hz

c = speed of light = 3x10⁸ m/s

So = c /

       = 287.1 m

(2) We know that wave length , = c /

Where

= frequency = 835.6 MHz = 835.6x10⁶ Hz

c = speed of light = 3x10⁸ m/s

So = c /

       = 0.359 m

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(1) We know that Energy , E = h

Where

= frequency = 104.2 MHz = 104.2x10⁶ Hz

h = planck's constant = 6.626x10^-34 Js

So E = h

        = 6.904x10^-26 J

(2) We know that Energy , E = h

Where

= frequency = 1070 kHz = 1070x10³ Hz

h = planck's constant = 6.626x10^-34 Js

So E = h

        = 7.089x10^-28 J

(3) We know that Energy , E = h

Where

= frequency = 835.6 MHz = 835.6x10⁶ Hz

h = planck's constant = 6.626x10^-34 Js

So E = h

        = 5.536x10^-25 J