Question

Plane microwaves are incident on a thin metal sheet that has a long, narrow slit of width 4.8 cm in it. The microwave radiation strikes the sheet at normal incidence. The first diffraction minimum is observed at θ = 42°. What is the wavelength of the microwaves?

Answer 1

Answer:

$\lambda = 3.21 \ cm$

Explanation:

given,                                                                            

width of narrow slit = 4.8 cm                                

minimum angle of diffraction = θ = 42°                

wavelength of the microwave = ?                            

condition for the diffraction for single slit diffraction

      $d sin \theta = m \lambda$              

for the first minima m = 1                          

      $d sin \theta = \lambda$                  

wavelength of microwave radiation is equal to

      $\lambda = d sin \theta$                

      $\lambda = 4.8\times sin 42^0$  

      $\lambda = 3.21 \ cm$                

the wavelength of microwaves is equal to $\lambda = 3.21 \ cm$