WHat is the direction of force between two parallel conductors carrying current in same direction

WHat is the direction of force between two parallel conductors carrying current in opposite direction?

Derive an expression for the force between twolong parallel conductors carrying current in the same direction.What type of force is acting between two long parallel conductors carrying current in the same direction ? Using the expression define S.l. unit of current.

Find the magnitude and direction of the force between two parallel conducting wires carrying current and hence define ampere.

What is the direction of gravitational force betwen two particles?