A Level Physics Practice Exam

To determine the angle of diffraction for the second order diffracted beam, we can use the grating equation, which is given by:

\[ d \sin(\theta) = m \lambda \]

where \( d \) is the grating spacing, \( m \) is the order of diffraction, \( \lambda \) is the wavelength of the light, and \( \theta \) is the angle of diffraction.

In this case:

- The wavelength \( \lambda = 590 \, \text{nm} = 590 \times 10^{-9} \, \text{m} \),

- The grating spacing \( d = 1.67 \times 10^{-6} \, \text{m} \),

- The order \( m = 2 \) for the second order beam.

Substituting these values into the grating equation:

\[ 1.67 \times 10^{-6} \sin(\theta) = 2 \times (590 \times 10^{-9}) \]

Calculating the right-hand side:

\[ 2 \times (590 \times 10^{-9}) = 1180 \times 10^{-9} = 1.18