Q$9.$ A $0\mathrm{.}50$ m rod slides relative to stationary rails, as shown in the drawing. A uniform magnetic field of $0\mathrm{.}20$T is directed parallel to the normal of the loop created by the rod and the rails. The rod slides such that the distance $x$ increases from $0\mathrm{.}80$ m to $1\mathrm{.}20$ m in $0\mathrm{.}20$ seconds.

a$)$ Calculate the change of the magnetic flux through the loop.

b$)$ Determine the magnitude of the induced EMF across the rod.

c$)$ Which end of the rod will be at a higher potential?

Q$10.$ When the current passing through a solenoid coil of $20$ closely wound turns increases from $500$ mA to $300$ mA in $0\mathrm{.}04$ seconds, an EMF of $250$ mV is induced across the coil. Does the amount of energy stored in the magnetic field generated by the coil increase or decrease due to the change in the current? Determine the amount of increase$/$decrease$.$