Why does stone lying in the sun get heated up much more than water lying for the same duration of time?

When a current carrying conductor is placed in a magnetic field, it experiences a mechanical force. What should be the angle between the magnetic field and the length of the conductor so that the force experienced is:

(i) Zero

(ii) Maximum?

Why is it not advisable to use a piece of copper wire as fuse wire in an electric circuit?

Two metallic blocks P and Q having masses in ratio 2 : 1 are supplied with the same amount of heat. If their temperatures rise by same degree, compare their specific heat capacities.