Quick questions on Uniform circular motion: WACE Year 12 Physics Unit 3

For a ball on a string swung in a horizontal circle, the horizontal component of the string tension supplies $F_c$ while the vertical component balances weight. For a car on a flat road, static friction between the tyres and road provides the entire centripetal force, so the maximum cornering speed is set by $\mu mg=mv^2/r$.

On a frictionless banked track of angle $\theta$, the horizontal component of the normal force supplies $F_c$ while the vertical component balances weight:

In a vertical circle the speed varies, so it is not strictly uniform, but the centripetal relationship still holds instant by instant. At the top, gravity and the normal force (or tension) both point inward:

In any answer, first state which physical force points toward the centre, then equate it to $mv^2/r$. Examiners reward this identification heavily, because it shows you understand that the centripetal force is supplied, not added.