Question

A short dipole is placed along x-axis with centre at origin. The electric field at a point P, which is at a distance r from origin such that $\overset{\rightarrow}{OP}$ = $\overset{\rightarrow}{r}$ makes an angle of 45⁰ with x-axis, is directed along a direction making –

• A. Tan^–1(0.5) with x-axis
• B. p/4 + tan^–1(0.5) with x-axis
• C. p/4 + tan^–1(0.5) with y-axis
• D. Tan^–1(0.5) with y-axis

Answer 1

Answer: (B)

p/4 + tan^–1(0.5) with x-axis

Answer 2

Angle of resultant with x-axis will be a + q.

Angle = tan^–1 $\left( \frac { \tan \theta } { 2 } \right)$+ q

= tan^–1 $\left( \frac { \tan 45 } { 2 } \right)$+ q

= tan^–1 (0.5) + p/4