Question

As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that the microwaves "herd" electrons into "pointy" areas of the metal object, from which the electrons jump from one part of the object to another. The other friend says that the sparks are caused by the photoelectric effect. Prove or disprove the latter idea using basic physics. Suppose the typical work function of the metal is roughly 4.910×10−19 J.4.910×10−19 J. Calculate the maximum wavelength in angstroms of the radiation that will eject electrons from the metal.

Answer 1

Answer:

$4.048\times 10^{-7}\ m$

Explanation:

h = Planck's constant = $6.626\times 10^{-34}\ m^2kg/s$

c = Speed of light = $3\times 10^8\ m/s$

E = Energy = $4.91\times 10^{-19}\ J$

Wavelength ejected is given by

$\lambda=\dfrac{hc}{E}\\\Rightarrow \lambda=\dfrac{6.626\times 10^{-34}\times 3\times 10^8}{4.91\times 10^{-19}}\\\Rightarrow \lambda=4.048\times 10^{-7}\ m$

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is $4.048\times 10^{-7}\ m$