Physics - electrons and Protons

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Question - 1

Strong argument for the particle nature of cathode rays is to

  • A Produce fluorescence
  • B travel throught vacuum
  • C get deflection by electric and magnetic fields
  • D cast shadow

Question - 2

An electron is projected pointing in the same direction of electric and magnetic fields.  Then

  • A the electron turns to right
  • B the electron turns to right
  • C the electron continues to move in the same direction but with less velocity
  • D the electron continues to move in the same direction but with increased velocity

Question - 3

Cathode rays are projected pointing normal to the direction of electric field.  Their path is

  • A straight line
  • B ellipse
  • C circle
  • D parabola

Question - 4

Neon lamps work in the region of

  • A cathode glow
  • B negative glow
  • C positive column
  • D Crooke's dark space

Question - 5

The specific charge of electron is 

  • A \(1.6\times10^{-19}C\)
  • B \(9.1 \times10^{-31}kg\)
  • C \(1.76\times10^{11}C kg^{-1}\)
  • D \(5.7\times10^{-12}kg C^{-1}\)

Question - 6

Gases begin to conduct electricity at low pressure because

  • A The electrons in atoms can move freely at-low pressure
  • B Atoms break up into electrons and protons
  • C Colliding electrons can acquire higher kinetic energy due to increased mean free path causing ionisation of atoms
  • D At low pressure gas turn into plasma

Question - 7

Proton is 1840 times heavier than an electron.  The ratio of specific charge of \(\alpha \)-particle to that of electron is 

  • A 1840
  • B \((1840)^{-1}\)
  • C \((3680)^{-1}\)
  • D 3680

Question - 8

Energy of an electron can be increased by

  • A making them fall from a great height
  • B moving them through an electric potential
  • C passing them through lead block
  • D passing them through high magnetic field

Question - 9

The specific charge of a proton is 9.6\(\times 10^{7}C \ kg^{-1}\).  That for \(\alpha \) particle will be

  • A 9.6\(\times 10^{7}C \ kg^{-1}\)
  • B 4.8\(\times 10^{7}C \ kg^{-1}\)
  • C 2.4\(\times 10^{7}C \ kg^{-1}\)
  • D 38.4\(\times 10^{7}C \ kg^{-1}\)

Question - 10

A proton moving with velocity \(\vartheta \) is acted upon by electric field E and magnetic filed B.  The proton will move undeflected if

  • A E is perpendicular to B
  • B E is parallel to \(\vartheta \) and perpendicular to B
  • C E, B and \(\vartheta \) are mutually perpendicular and \(\vartheta ={E\over B}\)
  • D E and B both are parallel to \(\vartheta \).
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