A solid weighs 0.09N in air and 7.0N when totally immersed in water . calculate the relative density of the solid . ​

be subject to a force andchange its motion

if they have a finite resultant

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.