When a phone is inside microwave oven and if we call it using wifi the phone doesnt recive call as frequency of wifi is same as frequency of wave generated in oven as there is a mesh like thing which blocks waves but how can we recive same whatsapp call when phone is inside trousers as holes in it are still smaller than mesh holes?
Metal blocks microwaves. Cloth does not because it is not metal.
The purpose of the holes in the microwave door screen is to allow visible light to pass through so the user can view the oven contents. Microwaves don’t pass through the holes in the metal mesh screen of the door because the diameter of the holes is about a millimeter and is much less than the wavelength of the microwaves, which is about 120 mm. The wavelength of visible light, on the other hand, is much smaller than the holes in the screen which therefore allows light to pass through.
Hope this helps