A square loop of side 2 ~cm enters a magnetic field with a constant...

As the loop moves, there are three cases. (i) When the loop moves fully outside the magnetic field, there is no change in flux. $\therefore \varepsilon=\frac{d \phi}{d t}=0$ (ii) When the loop is entering/leaving the area of magnetic field. $\begin{gathered}\varepsilon=B L V=(0.9)\left(2 \times 10^{-2}\right)\left(2 \times 10^{-2}\right) \\ =2 \times 10^{-4} \mathrm{~V}\end{gathered}$ As flux is in opposite direction to magnetic field. $\varepsilon$ when loop enters the field $=-2 \times 10^{-4} \mathrm{~V}$ $=2 \times 10^{-4} \mathrm{~V}$ (iii) When moving inside the magnetic field. $\frac{d \phi}{d t}=0$ $\therefore$ No emf is induced.