The phosphor bronze strip is used in a moving coil galvanometer because

A uniform circular wire loop is connected to the terminals of a battery. The magnetic field induction at the centre due to $ABC$ portion of the wire will be (length of $ABC=l_1,$ length of $ADC=l_2$)

A cylindrical conductor of radius $R$ is carrying a constant current. The plot of the magnitude of the magnetic field $B$ with the distance $d$ from the centre of the conductor, is correctly represented by the figure:

An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current $\text{'}I\text{'}$ along the same direction is shown in Fig. Magnitude of force per unit length on the middle wire$\text{'}B\text{'}$ is given by

A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is $B$ . It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of $n$ turns will be