Suggested languages for you:

Q. 10 - Excercises And Problems

Expert-verified
Found in: Page 1082

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# An electron in a cathode-ray beam passes between long parallel-plate electrodes that are apart. A , wide magnetic field is perpendicular to the electric field between the plates. The electron passes through the electrodes without being deflected if the potential difference between the plates is .a. What is the electron’s speed?b. If the potential difference between the plates is set to zero, what is the electron’s radius of curvature in the magnetic field?

(a) Speed of electron

(b) Electrons radius of curvature in magnetic field.

See the step by step solution

## Part(a) Step 1: Given information

parallel plate electrode

length of electrode:

width(d): ;

magnetic field(B)= (perpendicular to electric field)

No deflection when

## Part(a) Step 2: Finding velocity of electron

Using formula:

When electron pass without deflection then (where v is speed of electron, E is electric field)

Hence, electron's speed is

## Part(b) step 1: Given information

parallel plate electrode

mass of electron(m)=

charge on electron(q)=

magnetic field(B)= (perpendicular to electric field)

velocity of electron=(from part (a))

## Part(b) Step 2: Finding radius of curvature

In presence of magnetic field only, we know that

where R is radius, m is mass of electron, v is its velocity, q is charge, B is magnetic field present;

Hence, electrons radius of curvature in magnetic field is