Question

In a cyclotron, a charged particle :

• A. Undergoes acceleration all the time.
• B. Speeds up between Dees because of magnetic field.
• C. Speeds down between Dees because of electric field.
• D. Slows down between the Dees and speeds up within the Dees.

Answer 1

The correct option is A Undergoes acceleration all the time.

In a cyclotron, the charged particle moves in a spiral path with increasing radius.


The charged particle experiences centripetal force inside the Dees due to magnetic force only.

$\therefore F_m=qvB\sin {90}^{\circ }=qvB$

This force makes the charged particle moves in uniform circular path inside the Dees and hence the charged particle changes its direction all the time inside the Dees.

Between the Dees, the charged particle gets accelerated because of the presence of electric field $\overrightarrow{E}$, thus, its speed increases between the Dees because of it.

Hence, charged particle remains accelerated all the time.