A metal bar moves with constant speed **to the right**. A constant magnetic field points **out of the page**. What happens to the electrons in the bar (in the frame of the moving bar)?
1. Nothing
2. They move upward
3. They move downward
4. They move left
5. They move right
Note:
* Correct Answer: B
One end of rectangular metal loop enters a region of constant uniform magnetic field $\mathbf{B}$, with initial constant speed $v$, as shown. What direction is the magnetic force on the loop?
<img src="./images/loop_entering_Bfield.png" align="left" style="width: 500px";/>
1. Up the "screen" $\uparrow$
2. Down the "screen" $\downarrow$
3. To the right $\rightarrow$
4. To the left $\leftarrow$
5. The net force is zero
Note:
* Correct Answer: D
One end of rectangular metal loop enters a region of constant uniform magnetic field $\mathbf{B}$, out of page, with constant speed $v$, as shown. As the loop enters the field is there a non-zero emf around the loop?
<img src="./images/loop_entering_Bfield.png" align="left" style="width: 500px";/>
1. Yes, current will flow CW
2. Yes, current will flow CCW
3. No
Note:
* Correct Answer: A