As the electron beam is not deflected, then or FmBevv=Fe=Ee=BE As the electron moves from cathode to anode, its potential energy at the cathode appears as its kinetic energy at the anode. If V is the potential difference between the anode and cathode, then potential energy of the electron at cathode =eV. Also, kinetic energy of the electron at anode =21mv2. According to law of conservation of energy 21mv2v=eV=m2eV From Eqs. (i) and (ii), we have m2eVme= BE=2VB2E2
A beam of cathode rays is subjected to crossed Electric ( E ) and Magnetic fields (B). The fields are adjusted such that the beam is not deflected.…
NEET UG 2010 — Physics Modern Physics
2010mcqeasy
A beam of cathode rays is subjected to crossed Electric ( E ) and Magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by (where V is the potential difference between cathod and anode)
Official previous-year question
Held on 30 Apr 2010 · Verified 9 Jul 2026.
Options
- A
2VE2B2
- B
E22VB2
- C
B22VE2
- D
2VB2E2
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