Question

The given diagram shows a negatively charged ball moving to the right below a wire carrying conventional current to the right. Both are in the plane of the screen.
What is the direction of the force on the negatively charged ball at the place it is pictured?

• A. Up towards the top of the screen
• B. Down towards the bottom of the screen
• C. Toward the left side of the screen
• D. Toward the right side of the screen
• E. The force is zero, since the negative charge is moving parallel to the current

Answer 1

The correct option is B Down towards the bottom of the screen

We apply Right hand thumb rule to find the direction of magnetic field at the place , where ball is placed , we find the direction of magnetic field at this place , into the plane of paper normally .

Now by applying the Fleming's left hand rule on the ball (taking direction of current , opposite to the motion of negatively charged ball ) we get direction of force , down towards the bottom of screen .