Questions

Pass input to XOR and give their outputs to OR gate, if your output is 0 both 8-bit signals are same.

OR

Pass input to XNOR and give their outputs to AND gate, if your output is 1 both 8-bit signals are same. 

In music, a fugue is a contrapuntal compositional technique in two or more voices, built on a subject that is introduced at the beginning in imitation and which recurs frequently in the course of the composition. 

Hence, the main theme of a fugue is called the subject.

A cell undergo meiosis, and it produces 4 haploid cells from a single diploid cell.

Hence, the given statement is true.

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

A rift valley is formed either due to upheaval of blocks on either sides of a fracture or due to subsidence of block between them.