Units And Measurements

In a single slit diffraction experiment, a slit of width $(0.016 \pm 0.002)$ mm is used to measure the wavelength of a monochromatic light source. In the diffraction pattern, the angular distance between the central maximum and first minimum is measured to be $(2^{\circ} \pm 40')$. The value of the fractional error in the measurement of wavelength is :

[Given : $\sin(2^{\circ}) = 0.035$]