Question

Consider the absorber-cover system data of a flat plate solar collector given below Material: Glass Number of covers: 2 Thickness of each cover: 4 mm Refractive index of the glass relative to air: 1.52 Extinction coefficient of glass: 10 Angle of incidence of beam radiation: 10˚ Plate absorptivity for solar radiation: 0.94 Diffusive reflectivity of two glass-cover system = 0.21
a)Angle of refraction is ______​

Answer 1

Answer:

6.6

Explanation:

n2/n1 =sin2/sin1

angle of refracation is 6.6

Answer 2

Answer:

Angle of refraction is equal to 6.54°.

Explanation:

We know, Snell's law :

                  $\frac{Sin\theta_{r} }{Sin\theta_{i}}=\frac{n_{1} }{n_{2} }$

Given that,

       The refractive index of glass to water $(\frac{n_{2} }{n_{1} }) =1.52$

        Angle of the incidence of the beam = 10°  

   Put these values in snell's law,

                              $Sin\theta_{r} =Sin\theta_{i}(\frac{n_{1} }{n_{2} } )$  

                                $Sin\theta_{r} = \frac{Sin10}{1.52}$

                     ∴         $Sin\theta_{r} = 0.114$

                     ∴               $\theta_{r} = 6.54$°