Home
Class 12
PHYSICS
A particle of mass mand charge q, moving...

A particle of mass `m`and charge `q`, moving with velocity `v` enters Region `II` normal to the boundary as shown in the figure. Region `II` has a uniform magnetic field `B` perpendicular to the plane of the paper . The length of the region `II` is `l`. Choose the correct choice(s).

A

The particle enters regions III only if its velocity `V gt (qlB)/(m)` .

B

The particle enters regions III only if its velocity `V gt (qlB)/(m)` .

C

Path length of the particle in region II is maximum when velocity `V = (qlB)/(m)`

D

Time spent in region II is same for any velocity `V` as long as the particle returns to region I .

Text Solution

Verified by Experts

The correct Answer is:
`A,C,D`
In region II the particle follows a circular path of radius
` r = (mv)/(qB)`
Therefore, the particle can enter III,ifr gt l i.e if
`v gt (qBl)/(m)`
In regin II the maximum path length is `r =l`
which gives `v =(qBl)/(m)`
The time period of the circular motion is
` T = (2pir)/(v) = (2pi)/(v) xx (mv)/(qB) = (2pi)/(qB)`
The particle will return to region I if the time spent by in region II is `(T)/(2) =(pim)/(qB)` which is indepedndent of the velocity Hence the correct choices are `(A)` `(C)` and `(D)` .
Promotional Banner

Similar Questions

Explore conceptually related problems

A particle of mass m and charge Q moving with a velocity v enters a region on uniform field of induction B Then its path in the region is s

A particle of the mass m and cgharge q moves with a constant velocity v along the positive x- direction . It enters a region containing a uniform magnetic field B directed along the minimum value of v required so that the particle can just enter the region xgtb is

A circular coil carrying current is placed in a region of uniform magnetic field acting perpendicular to the plane of the coil as shown in figure. The correct choice among the following is

In a region of space a uniform magnetic field perpendicular to the plane of the page and directed towards reader exists. A particle has a trajectory as shown in fig. The particle is-

A particle of mass m carrying charge q is accelerated by a potential difference V. It enters perpendicularly in a region of uniform magnetic field B and executes circular arc of radius R, then q/m equals

A positive charge particle of charge q, mass m enters into a uniform magnetic field with velocity v as shown in the figure. There is no magnetic field to the left of PQ. Find time spent

A charged particle ( mass m and charge q) moves along X axis with velocity V_0 . When it passes through the origin it enters a region having uniform electric field vecE=-E hatj which extends upto x=d . Equation of path of electron in the region . x gt d is :