A beam of cathode rays is subjected to c...

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

A

`(B^(2))/(2VE^(2))`

B

`(2VB^(2))/(E^(2)`

C

`(2VE^(2))/(b^(2))`

D

`(E^(2))/(2VB^(2))`

Verified by Experts

The correct Answer is:

D

`qvB=qEimplies V=(E )/(B)`
But`(1)/(2)mv^(2)=qV so (q)/(m)=(v^(2))/(2V)=(E ^(2))/(2VB^(2))`

Similar Questions

Explore conceptually related problems

X-ray beam can be deflected

The ratio e//m i.e. specific , for a cathode ray

If cathode rays are projected at right angles to a magnetic field, their trajectory is:

Can a photon be deflected by an electric field ? By a magnetic field ?

Cathode rays have same charge to mass ratio as

An electric field (vec E) and a magnetic field (vec B)exist in a region . The fields are not perpendicular to each other.

What is the nature of charge on (i) cathode rays (ii) anode rays?

Can an electromagnetic wave be deflected by an electric field? By a magnetic field ?