A magnetic lens can focus
1. sound waves
2.rays
3. a beam of light
4. a beam of electrons
Posted Date:-2021-10-15 06:52:53
Einsteins mass-energy relation is
1. E = mc
2. E = mc2
3.E = m2c
4.E = m2c2
Posted Date:-2021-10-15 06:52:53
Electron microscope works in
1.vacuum
2. atmospheric pressure
3. very high pressure
4. any pressure
Posted Date:-2021-10-15 06:52:53
he focal length of magnetic lens used in an electron microscope depends on
1. the velocity of electrons
2. the magnitude of current passing through energizing coils
3. the medium in between energizing coils
4. all the above
Posted Date:-2021-10-15 06:52:53
In an electron microscope electrons are focused by means of
1. convex lens
2. concave mirror
3.liquid lens
4. magnetic lens
Posted Date:-2021-10-15 06:52:53
In an electron microscope the object is enclosed in
1. a glass plate
2. liquid
3. water
4. colloidal film
Posted Date:-2021-10-15 06:52:53
In electron microscope the electron beam is focused by varying the
1. wavelength of electron
2. current through the emerging coil
3. velocity of electron
4. thickness of colloidal film
Posted Date:-2021-10-15 06:52:53
The de Broglie wavelength associated with an electron moving with a speed of 107m/s
1.0.728
2.7.28
3.72.8
4.728
Posted Date:-2021-10-15 06:52:53
The de Broglie wavelength of an electron of kinetic energy 500 e V is
1.54.92
2.0.5492
3.5492
4.5.492
Posted Date:-2021-10-15 06:52:53
The momentum of an electron if its wavelength is 2� is 2.3 ? 10-24 kg ms-1 3.315 ? 10-24 kg ms-1
1. 2.3 ? 10-24 kg ms-1
2.3.315 ? 10-24 kg ms-1
3.1.3 ? 10-24 kg ms-1
4.13 ? 10-24 kg ms-1
Posted Date:-2021-10-15 06:52:53
The special feature of an electron microscope is its
1. high resolving power
2. compactness
3. low cost
4. resolving power being equal to that of an optical microscope
Posted Date:-2021-10-15 06:52:53
The wave associated with a moving particle is called mechanical wave
1. longitudinal wave
2. mechanical wave
3.de Broglie wave.n
4.Plancks wave
Posted Date:-2021-10-15 06:52:53
The wave nature of electron is applied in the field of
1. electron microscopy
2. fusion reactors
3. artificial radioactivity
4. satellite launching
Posted Date:-2021-10-15 06:52:53