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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 cathode and anode).
Options
(a) B² / 2VE²
(b) 2VB² / E²
(c) 2VE² / B²
(d) E² / 2VB²
Correct Answer:
E² / 2VB²
Explanation:
For no deflection of beam, eE = evB ⇒ v = E/B
Also, 1/2 mv² = eV ⇒ v = E/B
e/m = v² / 2V = E² / 2VB²
Related Questions: - Find out the e.m.f. produced when the current changes from 0 to 1 A in 10 sec.
- A cylindrical tank is filled with water to a level of 3m. A hole is opened at a height
- When the angle of incidence is 60° on the surface of a glass slab, it is found
- Magnetic flux φ (in weber) linked with a closed circuit of resistance 10 Ω varies
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Topics: Dual Nature of Matter and Radiation
(150)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Find out the e.m.f. produced when the current changes from 0 to 1 A in 10 sec.
- A cylindrical tank is filled with water to a level of 3m. A hole is opened at a height
- When the angle of incidence is 60° on the surface of a glass slab, it is found
- Magnetic flux φ (in weber) linked with a closed circuit of resistance 10 Ω varies
- Large transformers, when used for some time, become hot and are cooled by circulating
Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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