Question

The most common method of defrosting frozen meat/fish is by pouring water on them or holding them under the sink tap. This definitely is a direct application of the fact that if you pour water on ice it melts.

Is it possible to freeze water by dropping ice on it. Give logical explanation of your answer

Answer 1

if you put ice and water together in a cup, heat will flow from the water to the ice until they reach thermal equilibrium, which will be a temperature between the water's initial temperature and the ice's initial temperature. If the temperature of the ice was low enough or if there was enough ice for the water to keep giving away heat, then the water will freeze.Otherwise it will not freeze.

Why don't you usually see that happening?
Well, regular ice cubes are probably around −5 °C, and there usually is more water than ice in a cup, so before the water has a chance to reach 0 °C all the ice has already melted. Besides that, the ice is receiving heat from the room, unless you're in a place where's below 0 °C.