Which two microscopes generate three-dimensional images?
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A microscope can resolve as two distinct objects of featuresthat are no closer than the wavelength of the light or electronsused for the observation.a) with electron microscopes, what energy is needed for aresolution of 0.4Ã
b) what photon energy would be required of an optical microscopefor the same resolution?
Electron microscopes use the wave characteristic of fast electrons.The electrons are accelerated in an electric field which is createdby a potential difference of a few 10 kV for scanning electronmicroscopes and 100 â200 kV for transmission electron microscopes.Note: At these voltages the electrons are alreadyrelativistic.Calculate the de Broglie wavelength of electrons in an electronmicroscope which was accelerated to a speed of 1000 km/s.
Which of the following statements are true of virtual images? Identify all that apply.
1. Virtual images are always upright.
2. Virtual images as formed by lenses are always located on the same side of the lens as the object.
3. Virtual images are only formed by diverging lenses, never by converging lenses.
4. Virtual images are always smaller than the object.
5. An image of a real object is formed; the image distance (s' or di) for virtual image is a – value.
6. An image of a real object is formed; the image height (h' or hi) for virtual images is a – value.
7. Virtual images have a – magnification value.
