Charge is sprayed onto a large non conducting belt above the left hand roller. The belt carries charge with a uniform surface charge density σ , as it moves with a speed v between the rollers as shown. The charge is removed by a wiper at right hand roller. For a point just above the sheet mark the correct option.

The moving charged belt is equivalent to a current carrying sheet which is carrying current in the direction of its velocity .

Magnetic field $\left(\overrightarrow{B}\right)$  produced by this belt is parallel to the plane of the belt and perpendicular to the velocity V of the belt  ( out of the plane of the figure ) .

$B =\frac{{\mathrm{\mu }}_0\mathrm{K}}{2}.\text{ Hence }\mathrm{K}=\mathrm{\sigma V}= Current per unit width of the belt$

 $\overrightarrow{F}=\left(-e\right)\overrightarrow{V_e}\times \overrightarrow{\mathrm{B}}$ hence upwards