Physics SL Topic 5 Help

[Cici2017]

Hello 

I am having some trouble with these questions. Can someone help me? Thank you so much! 😀

 

 

[kw0573]

1. C Gravitational field strength is the net gravitational force per unit mass. Which mean upon a mass of 1 at P, there is not only a force of g to the left, there is also some force to the right. As the force are acted on opposite directions, the net gravitational force is less than g. 
2. C Currents that are in the same direction attract each other. Alternative solution using first principals: by right hand rule, the field lines point down to the right of both X and Y. By a different right hand rule, the force that exerts on a current into the page at downward field lines is acting towards the left.

3. B Field lines go from S to N inside a magnet and N to S outside a magnet (by definition). Field line at the electron points to the right. The velocity of the positive charge is in the opposite direction of the electron, so points down. Applying right hand rule correctly, the force on electron is out of page.