Physics, 29.02.2020 01:16, sunflowergirl6664

What are some drawbacks of electron microscopes? 3. If an object being viewed under the phase-contrast microscope has the same refractive index as the background material, how would it appear? +

Answers: 3

Show answers

Answers

answered: bobbye001

1. Some drawbacks of electron microscopes:

Price, size, repair, researcher learning and image artifacts arising from specimen preparation are the major drawbacks. This form of magnification is a massive, burdensome, costly piece of equipment, highly sensitive to vibration and exterior magnetic field.It must be held in an environment that is big enough to contain the microscope, as well as to secure and prevent any unwanted effect on the electrons.Upkeep includes ensuring balanced voltage supplies, electromagnetic coil / lens currents and cool water circulation so that the specimens are not destroyed or damaged by the heat released during the electrons energization process.

2. If an object being viewed under the phase-contrast microscope has the same refractive index as the background material than "it would be difficult to see because the phase contrast microscope amplifies differences in the refractive index".

Explanation:

In order to improve the comparison of transparent and colorless specimens with the light microscopy pictures, thus phase contrast is used. This allows the visualization of cells and cell elements which would be hard to see using a standard light magnification. The phase comparison does not involve the destruction, fixation or staining of cells.

Due to diffraction and scattering phenomena which exist at the edges of these objects, large, extended specimens are also quickly visualized with phase contrast optical. As light transits through one medium to another, the velocity is changed in proportion to the variations in the refractive index between the two media. Therefore, the wave is either increased or decreased in velocity whenever a coherent light wave produced by the oriented microscope filament progresses via a phase specimen with a particular thickness and refractive index.

answered: Guest

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

answered: Guest

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf, ℰ, to a battery's terminal voltage, v, current, i, and internal resistance, r, is ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

Other questions on the subject: Physics

Physics, 21.06.2019 22:30, christson805

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Answers: 2

continue

Physics, 22.06.2019 14:30, mangowammy

What conclusion can be made based on the temperature of soil when the light hits the soil at 0°, 45°, and 90° angles in section 2 of the experiment? did your results support your hypothesis? why or why not?

Answers: 1

continue

Physics, 22.06.2019 17:30, RegencySlayer5304

Alarge cruise ship of mass 7.00 ✕ 107 kg has a speed of 11.6 m/s at some instant. (a) what is the ship's kinetic energy at this time? (b) how much work is required to stop it? (give the work done on the ship. include the sign of the value in your answer.) (c) what is the magnitude of the constant force required to stop it as it undergoes a displacement of 3.00 km?

Answers: 2

continue

Physics, 22.06.2019 18:30, ayahabdulhaqq2

An electron in an x-ray machine is accelerated through a potential difference of 1.00 × 104 v before it hits the target. what is the kinetic energy of the electron in electron volts?

Answers: 2

continue

Do you know the correct answer?

What are some drawbacks of electron microscopes? 3. If an object being viewed under the phase-contra...