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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
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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
- A step-up transformer operates on a 230 V line and supplies a current of 2 A.
- If ₉₂U²³⁸ undergoes successively 8 ∝-decays and 6 β-decays, the resulting nucleus is
- Two particles A and B having equal charges, after being accelerated
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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
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