Which statement(s) among the following are incorrect:
(i) A negative test charge experiences a force opposite to the direction of the field.
(ii) The tangent drawn to a line of force represents the direction of electric field.
(iii) The electric field lines never intersect.
(iv) The electric field lines form a closed loop.

The electric field lines originates from a positive charge and ends at a negative charge and these field lines are also known as electric lines of forces. The direction of electric filed lines is from positive to negative. 

One of the properties of the electric lines of forces is, the tangent drawn at a point on the electric field gives the direction of electric force.

Therefore, the electric field lines never form a closed-loop because if they do, there will be two directions of forces at the point of intersection which is not possible for electric lines of forces.

Force experienced by a charge $q$in an electric field is, $F=qE$if the charge is $-q$or negative test change then force is$F=-qE.$ Thus, a negative test charge experiences a force opposite to the direction of the field.

Option (i) and (iii) are true