Which of the following is used as an antibiotic?

Which phase of the cell cycle is characterized by the replication of $DNA$ and the synthesis of histone proteins?

The combined equation of the bisectors of the angles between the lines joining the origin to the points of intersection of the curve $x^2+y^2+xy+x+3y+1=0$ and the line $x+y+2=0$ is

Which one of the following reactions occurs at the anode in the Castner process of extracting sodium metal?

Which of the following compounds does not contain a peroxide ion?

$A$ steady current flows in a long wire. It is bent into a circular loop of one turn and the magnetic field at the centre of the coil is $B$. If the same wire is bent into a circular loop of $n$ turns,the magnetic field at the centre of the coil is