A diffraction grating is to be used to find the wavelength of the emission spectrum of a gas. The grating spacing is not known, but light of a known wavelength of 632.8 nm is deflected by 43.2° in the second order by this grating. Light of the wavelength to be measured is deflected by 34.9° in the second order. What is the wavelength of the light that is to be measured?

528.9 nm

Explanation:

For a grating dsinθ = mλ where m = order of grating, d = grating space, λ = wavelength of light and θ = angle of deflection of light

First, we find the grating space d = mλ/sinθ where m = 2 for second order, λ = 632.8 nm = 632.8 × 10⁻⁹ m, θ = 43.2°

d = mλ/sinθ = 2 × 632.8 × 10⁻⁹ m ÷ sin43.2° = 1.849 × 10⁻⁶ m = 1.849 μm

We now find the wavelength of the light to be measured from λ = dsinθ/m

Here, θ = 34.9° and m = 2 for second order. So, we have

λ = dsinθ/m = 1.849 × 10⁻⁶ m × sin34.9° ÷ 2 = 0.5289 × 10⁻⁶ m = 528.9 nm

In this excerpt from Act 3, of "A Doll's House", the prediction that the text best supports is Nora is going to leave Helmer and the children. After Torvald has threatened Nora that she is not going to be allowed to raise their children they argue about their married life. Nora states that she has never been happy and that she has been treated like a doll, admired and played with. We may predict that Nora needs to be herself, she needs to find herself before anything else.