A uniform metallic wire having resistance $4 \Omega$ is bent to form a square loop (ABCD) (see figure). A resistance of $2 \Omega$ is connected between points $B$ and $D$ and a battery of 2 V is connected across points $A$ and $C$ as shown in the figure. Now the value of current $(l)$ is :

A galvanometer of resistance $100 \Omega$ gives full scale deflection for a current of 1 mA . It is converted into an ammeter of range $0-10 \mathrm{~A}$. The shunt required is:

In a metre bridge experiment (see figure), the positions of the cell, $E$, and galvanometer, $G$, are interchanged. We shall observe in the galvanometer: