Calculate the angle at which first order reflection will occur in an X-ray spectrometer when X-rays of wavelength `1.54Å` are diffracted by the atoms of a crystal given that interplanar distance is `0.04Å`.

Explanation

To calculate the angle at which first order reflection will occur in an X-ray spectrometer, we can use Bragg's Law, which is given by the equation:

\[ n\lambda = 2d \sin \theta \]

Where:
- \( n \) = order of reflection (for first order reflection, \( n = 1 \))
- \( \lambda \) = wavelength of the X-rays
- \( d \) = interplanar distance
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