Answer to Question #182036 in Electricity and Magnetism for Dion Gray

Question

If an alpha particle has a velocity of magnitude 500m/s and travels horizontally in space in which there is an upward directed uniform electric field of magnitude 35N/C and a uniform magnetic field where the magnetic field makes an angle of 46⁰ with the particle's velocity vector such that it causes the alpha particle to pass through space undeflected,

How does the presence of the magnetic field causes the alpha particle to pass through undeflected and what happens to the alpha particle in the presence of the electric field?

Answer 1

To be given in question

Velocity $v_{x}=500meter/sec$

$E=35N/c$

$\theta =46°$

To be asked in question

Magnetic field (B)=?

We know that

$qE=q(v\times B)$

$qE=qv Bsin\theta$

Put values

$E=Bvsin\theta$

$B=E/vsin\theta$

$B=\frac{35}{500sin46°}$

$B=0.09731 Tesla$