Anelectron gun with its collector at a potential of 100 V fires outelectrons in a spherical bulb containing hydrogen gas at low pressure(∼10−2mm of Hg). A magnetic field of 2.83 × 10−4T curves the path of the electrons in a circular orbit of radius 12.0cm. (The path can be viewed because the gas ions in the path focusthe beam by attracting electrons, and emitting light by electroncapture; this method is known as the ‘fine beam tube’method. Determine e/mfrom the data.
Anelectron gun with its collector at a potential of 100 V fires outelectrons in a spherical bulb containing hydrogen gas at low pressure(∼10−2mm of Hg). A magnetic field of 2.83 × 10−4T curves the path of the electrons in a circular orbit of radius 12.0cm. (The path can be viewed because the gas ions in the path focusthe beam by attracting electrons, and emitting light by electroncapture; this method is known as the ‘fine beam tube’method. Determine e/mfrom the data.
Potentialof an anode, V =100 V
Magneticfield experienced by the electrons, B= 2.83 ×10−4T
Radiusof the circular orbit r= 12.0 cm = 12.0 × 10−2m
Massof each electron = m
Chargeon each electron = e
Velocityof each electron = v
The energyof each electron is equal to its kinetic energy, i.e.,
Itis the magnetic field, due to its bending nature, that provides thecentripetal force 
for the beam. Hence, we can write:
Centripetalforce = Magnetic force
Puttingthe value of vin equation (1), we get:
Therefore,the specific charge ratio (e/m)is
Potentialof an anode, V =100 V
Magneticfield experienced by the electrons, B= 2.83 ×10−4T
Radiusof the circular orbit r= 12.0 cm = 12.0 × 10−2m
Massof each electron = m
Chargeon each electron = e
Velocityof each electron = v
The energyof each electron is equal to its kinetic energy, i.e.,
Itis the magnetic field, due to its bending nature, that provides thecentripetal force for the beam. Hence, we can write:
Centripetalforce = Magnetic force
Puttingthe value of vin equation (1), we get:
Therefore,the specific charge ratio (e/m)is
