Question

The variation of x- component of external electric field with x-coordinate in a region is given by the adjacent graph. A small electric dipole having dipole moment $P_{0}\widehat{i}$ is placed at origin in this electric field, then net force on dipole if y and z component of electric field is zero (q is the angle made by tangent of graph at orgion with x-axis)

• A. P₀ tanq in the positive x-direction
• B. P₀ tanq in the negative x-direction
• C. Zero
• D. P₀ tanq in the positive y-direction

Answer 1

Answer: (B)

P₀ tanq in the negative x-direction

Answer 2

U = –P₀ E_x cosq

F = –= P₀

= P₀ × slope of graph

= P₀ × (–tanq)

= – P₀ tanq i