Physics · Force on a moving charge in uniform magnetic and electric fields
Assertion Cyclotron does not accelerate electron. Reason Mass of the electrons i
Assertion Cyclotron does not accelerate electron. Reason Mass of the electrons is very small.
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Both Assertion and Reason are incorrect
Step-by-step solution
The cyclotron relies on a constant cyclotron frequency f = qB/(2πm) for acceleration. Electrons have a very small mass, so their cyclotron frequency is extremely high, and they quickly reach relativistic speeds where the mass increases, causing the frequency to shift and resonance to be lost. Thus, cyclotrons are ineffective for electrons, and the small mass is the direct cause.
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