PLEASE HELP.
Another student made an electromagnet with an iron nail with eight coils of wire wound around it connected to a 2-V battery. She wants to increase the strength of the electromagnet. What changes can she make to her design to increase its strength? Select all that apply.

wrap more coils of wire around the nail

use two 1-V batteries instead of a 2-V battery

use a longer wire

use a 4-V battery

Jazelle has five different-sized magnets. She puts each magnet far away from a paper clip and slowly moves it closer until it attracts the paper clip. She records the distance between the magnet and the paper clip when it attracts. What is Jazelle's experiment designed to test?

how the type of paper clip affects the way in which it reacts to the force of a magnet

how the magnetic force of a magnet affects the movement of an object

how the size of a paperclip affects the strength of its magnetic pull on objects

how the size of a magnet affects the strength of its magnetic pull on objects

Kayla has two magnets. She would like to know how much magnetic energy is stored in each one. What would be the best way for her to determine which magnet has the most magnetic energy?

Attach wires to the ends of each magnet and measure the currents going through the wires

Measure how close each magnet can get to a metal object before picking it up.

Record the mass of each magnet by measuring it on a balance scale.

Put each magnet into a beaker of water to see how much water it displaces