thesportszones.com – MCQs, Mock Tests | General Science Basic Science De Broglie Waves

1 The de Broglie wavelength of an electron of kinetic energy 500 e V is

A 54.92 B 0.5492 C 5492 D 5.492

2 A magnetic lens can focus

A sound waves B rays C a beam of light D a beam of electrons

3 In an electron microscope electrons are focused by means of

A convex lens B concave mirror C liquid lens D magnetic lens

4 The wave associated with a moving particle is called mechanical wave

A longitudinal wave B mechanical wave C de Broglie wave.n D Plancks wave

5 The momentum of an electron if its wavelength is 2ï¿½ is 2.3 ? 10-24 kg ms-1 3.315 ? 10-24 kg ms-1

A 2.3 ? 10-24 kg ms-1 B 3.315 ? 10-24 kg ms-1 C 1.3 ? 10-24 kg ms-1 D 13 ? 10-24 kg ms-1

6 The de Broglie wavelength associated with an electron moving with a speed of 107m/s

A 0.728 B 7.28 C 72.8 D 728

7 he focal length of magnetic lens used in an electron microscope depends on

A the velocity of electrons B the magnitude of current passing through energizing coils C the medium in between energizing coils D all the above

8 In electron microscope the electron beam is focused by varying the

A wavelength of electron B current through the emerging coil C velocity of electron D thickness of colloidal film

9 Einsteins mass-energy relation is

A E = mc B E = mc2 C E = m2c D E = m2c2

10 The special feature of an electron microscope is its

A high resolving power B compactness C low cost D resolving power being equal to that of an optical microscope

11 Electron microscope works in

A vacuum B atmospheric pressure C very high pressure D any pressure

12 The wave nature of electron is applied in the field of

A electron microscopy B fusion reactors C artificial radioactivity D satellite launching

13 In an electron microscope the object is enclosed in

A a glass plate B liquid C water D colloidal film

General Science — Quiz