Answer Happy

(a) First watch the video "Ring Launcher". The apparatus can be simplified to the figure below. You will analyze why the ring jumps after the switch is closed. Iron core Coil Metal ring Step 1. With the switch open, what is the direction of the magnetic flux through the ring? Step 2. Mark the direction of the current in the coil after the switch is closed. Battery Switch Step 3. Draw magnetic field lines through the coil and the RING. Do you apply Right-Hand-Rule # 1 or #2? Label this field as the ORIGINAL field. If the current-carrying coil is treated as an equivalent bar magnet, mark its north and south poles. Step 4. From step 1 (switch open) to step 3, how does the magnetic flux through the RING change? Circle your answer: INCREASES, DECREASES, NO CHANGE Step 5. Apply Lenz's Law to determine the direction of the INDUCED magnetic field in the RING. Label the INDUCED field to differentiate from the ORIGINAL field. Step 6. Apply RIGHT-HAND-RULE #2 on the INDUCED FIELD to determine the direction of the INDUCED current in the RING. If the current-carrying RING is treated as an equivalent bar magnet, mark its north and south poles. TOWARD Step 7. Look at the equivalent bar magnets in step 3 and step 6 and recall how magnetic poles interact, answer the question: will the ring move toward or away from the coil? TOWARD AWAY From AWAY FROM (b) If the polarities of the battery are reversed, predict what will happen. Circle one answer: the ring will move the coil.
Apply the analyses on last page to this situation to verify your prediction. Iron core Coil Metal ring Step 1. With the switch open, what is the magnetic flux through the ring? Switch Step 2. Mark the direction of the current in the coil after the switch is closed. + Battery Step 3. Draw magnetic field lines through the coil and the RING. Do you apply Right-Hand-Rule #1 or #2? Label this field as the ORIGINAL field. If the current-carrying coil is treated as an equivalent bar magnet, mark its north and south poles. Step 4. From step 1 (switch open) to step 3, how does the magnetic flux through the RING change? Circle your answer: INCREASES, DECREASES, NO CHANGE Step 5. Apply Lenz's Law to determine the direction of the INDUCED magnetic field in the RING. Label the INDUCED field to differentiate from the ORIGINAL field. Step 6. Apply RIGHT-HAND-RULE #2 on the INDUCED FIELD to determine the direction of the INDUCED current in the RING. If the current-carrying RING is treated as an equivalent bar magnet, mark its north and south poles. Step 7. Look at the equivalent bar magnets in step 3 and step 6 and recall how magnetic poles interact, answer the question: will the ring move toward or away from the coil? TOWARD AWAY FROM