A cube of unit volume contains $ 35 \times 10^7 $ photons of frequency $ 10^{15} \, \text{Hz} $. If the energy of all the photons is viewed as the average energy being contained in the electromagnetic waves within the same volume, then the amplitude of the magnetic field is $ \alpha \times 10^{-9} \, \text{T} $. Taking permeability of free space $ \mu_0 = 4\pi \times 10^{-7} \, \text{Tm/A} $, Planck’s constant $ h = 6 \times 10^{-34} \, \text{Js} $ and $ \pi = \frac{22}{7} $, the value of $ \alpha $ is ____
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Correct Answer: 22 - 23
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