Gold ions (Au+) are accelerate to high speeds using electric fields.
These ions are then passed through a region where uniform electric E and magnetic B fields are present.
If the ions are traveling to the right, which configuration of E and B will serve as a velocity selector?
A. Electric field E up; Magnetic field B into the page
B. Electric field E down; Magnetic field B out of the page
C. Electric field E up; Magnetic field B out of the page
D. Electric field E down; Magnetic field B into the page
E. Both A and B
F. Both C and D
G. All of the above
i believe the answer is c, but im still a little unsure about this selection...
Why don't you analyze it? http://www.jiskha.com/display.cgi?id=1268497295
To determine the correct configuration of electric and magnetic fields that will serve as a velocity selector for gold ions, we can use the principles of the Lorentz force.
The Lorentz force is given by the equation F = q(E + v x B), where F is the force experienced by the charged particle, q is the charge of the particle, E is the electric field, v is the velocity of the particle, and B is the magnetic field.
In a velocity selector, we want the force on the charged particle to be zero. This means that the magnetic force (qv x B) and the electric force (qE) must balance each other out.
Let's analyze each option:
A. Electric field E up; Magnetic field B into the page:
In this configuration, the magnetic force (qv x B) will be downwards (according to the right-hand rule), but the electric force (qE) will also be downwards. These forces do not balance each other out, so this option is not correct.
B. Electric field E down; Magnetic field B out of the page:
In this configuration, the magnetic force (qv x B) will be upwards, and the electric force (qE) will also be upwards. These forces are in the same direction and can potentially balance each other out to provide a zero net force. This configuration could serve as a velocity selector.
C. Electric field E up; Magnetic field B out of the page:
Similar to option A, the magnetic and electric forces will be in the same direction (downwards). They cannot balance each other out, so this option is also incorrect.
D. Electric field E down; Magnetic field B into the page:
Similar to option B, this configuration can potentially provide a balance between the magnetic and electric forces, leading to a zero net force on the charged particle. It could potentially serve as a velocity selector.
E. Both A and B:
Option E includes both options A and B. Since option A is not a viable configuration for a velocity selector, option E is also not correct.
F. Both C and D:
Option F includes both options C and D. Option C is not a viable configuration for a velocity selector, so option F is also not correct.
G. All of the above:
Since options A, C, and E are not valid configurations, option G (all of the above) is also incorrect.
Therefore, the correct answer is option D: Electric field E down; Magnetic field B into the page.