Momentum: 3
Mass A has a mass of 10 kg while mass B has a mass of 20
kg. Which of these must be true?

D

Explanation:

F=ma

a=F/m

according to option D, F is constant

so acceleration is inversely proportional to mass and A has half the mass of B. Hence, acceleration of A will be twice of B if same force is applied.

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.