Question

Which of the following particles will have minimum frequency of revolution when projected with the same velocity perpendicular to a magnetic field?

विकल्प

•  Electron

• Proton

• He⁺

• Li⁺

Answer 1

Li⁺

Time period of the revolution of the particle, `T = (2pim)/(qB)`
As frequency is the reciprocal of time period, so  `f =(qB)/(2pim)`
The charge on all the four particles is same. But the mass is maximum for Li⁺. So, it will have the smallest frequency of revolution.