check
which of the following modifications to a solenoid would be most likely to decrease the strength of its magnetic field?
a. removing its iron rod core and increasing the number of coils
b. increasing the current and reducing the number of coils
c. reducing the number of coils and inserting an iron core
d. decreasing the current and reducing the number of coils
D
A stationary positive charge, Q, is located in a magnetic field, B, which is directed toward the right. What is the direction of the magnetic force on Q?
a. toward the right
b. up
c. down
d. there is no magnetic force
D
D is correct for the first question.
D is also correct for the second question since the charge is not moving. If it moved, there would be a force
So that dude is right. D. is the correct answer.
The direction of the magnetic force on a stationary positive charge, Q, located in a magnetic field, B, which is directed toward the right would be D. There is no magnetic force.
To determine the direction of the magnetic force on a stationary positive charge, Q, in a magnetic field, B, you can use the right-hand rule.
1. Point your right thumb in the direction of the velocity of the positive charge, Q. In this case, since the charge is stationary, the velocity is zero.
2. Extend your fingers in the direction of the magnetic field, B, which is directed toward the right.
3. Your palm will indicate the direction of the magnetic force on the positive charge, Q. Since there is no perpendicular component to the magnetic force, the answer is d. there is no magnetic force.