Consider a solid ball (sphere) of uniform density. Its radius is 10 cm and mass is 0.1 kg. What is the ball's moment of inertia if it is rotating about its center

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

d) physical means can be used to separate the components of air.

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.