Q. How are control signals achieve the particular operation?

The control signals are applied directly as binary inputs to the logic gates of the logic circuits. All these inputs are control signals that are applied to select a circuit (for illustration select or enable input) or a path (for illustration, multiplexers) or any other operation in logic circuits. 

A program execution comprises a sequence of instruction cycles. Every instruction cycle is made up of some sub cycles.  One such simple subdivision involves fetch, indirect, execute, and interrupt cycles, with only fetch and execute cycles always occurring. Every sub cycle includes one or more micro-operations.