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help stuck on question

me2gud4u · 2008-03-04 14:00:23

help. i have exam tomorrow and stuck a velocity selector is designed to allow charged particles with speed 4.5*10^3 ms-1 to pass through undeflected. The size of magnetic field is 0.96T, what is the size of the electric field. any help would be greatly appreciated.

04-03-2008 2:00pm

#1

me2gud4u

Closed Accounts Posts: 109 ✭✭

Join Date: March 2007

Posts: 80

help. i have exam tomorrow and stuck

a velocity selector is designed to allow charged particles with speed 4.5*10^3 ms-1 to pass through undeflected. The size of magnetic field is 0.96T, what is the size of the electric field.

any help would be greatly appreciated.

0

Comments

#2 04-03-2008 2:34pm

ApeXaviour

Registered Users, Registered Users 2 Posts: 5,523 ✭✭✭

Join Date: May 2004

Posts: 5279

Well what are you looking for? The electric field. How can a particle pass through undeflected? When the forces on it add up to zero. Which in this case (assuming the geometries are set up correctly) means when the magnetic force = static electric force from the electric field.

What's the force from a magnetic field on a moving charged particle?
F=qvB
and from an electric field E?
F=qE

Solve for E.

Make sense?

0