Question

Point $P$ lies on the axis of a dipole. If the dipole is rotated by ${90}^{\circ }$ anticlockwise, the electric field vector $\overrightarrow{E}$ at $P$ will rotate by :

• A. ${90}^{\circ }$ clock wise
• B. ${180}^{\circ }$ clock wise
• C. ${90}^{\circ }$ anti clock wise
• D. none

Answer 1

The correct option is A ${90}^{\circ }$ clock wise

Dipole means two equal and opposite charges. The directions of dipole moment and electric field are opposite. The dipole's direction is from negative charge to positive charge while that of electric field is from positive to negative charge. So when dipole rotate $90$ anti-clockwise, the electric field will rotate $90$ clockwise.