Faraday Lab (Lab Report Sample)

Faraday’s Electromagnetic Lab Learning Goal: NB: The correct Answer are Bolded To understand the conditions that cause the largest induced currents due to Faraday's law of induction. For this tutorial, use the PhET simulation Faraday’s Electromagnetic Lab. This simulation allows you to experiment with a pickup coil or a transformer to study Faraday’s law of induction 2653665107315 Click Run Now! Start the simulation. Part A: Faraday’s Law of Induction is a law of electromagnetism that demonstrates how changes in a magnetic field induces an electromotive force (emf) in a circuit thereby showing the relationship between electricity and magnetism. Recall that magnetic flux depends on magnetic field strength and the effective area the field is passing through. We’ll start our investigation by looking at the field strength around a bar magnet. Select the Bar Magnet tab. Deselect Show Compass, and drag the bar magnet to the center of the screen. Then, select Show Field Meter, which allows you to measure the strength of the magnetic field at any location. QUESTION: For which of the regions shown in the figure below is the magnetic field the strongest? Region C, adjacent to the magnet's North-Pole, exhibits the strongest magnetic field due to the concentration of field lines. Part B: Select the Pickup Coil tab, and place the bar magnet inside the coil containing two loops. QUESTION: Try to find a location where the stationary magnet induces a current in the coil and causes the light bulb to shine. Which of the following is correct? * There is no induced current in the coil, so the light bulb does not shine, if the magnet is stationary (for any location of the magnet). * The light bulb shines due to an induced current if one pole of the magnet is near the middle of the coil. * The light bulb shines due to an induced current if the magnet is inside the coil. Part C: Now, let’s look at a situation with changing flux. Starting from the far left of the screen, move the magnet to the right so it goes through the middle of the current loop at a constant speed and out to the right of the loop. QUESTION: Roughly where is the magnet when the light bulb is the brightest? (The brightness of the light bulb is depicted by the length of the rays emanating from it.) Select one of these choices: * The light bulb is brightest when either end of the magnet is in the middle of the coil. * The light bulb is brightest when the middle of the magnet is in the middle of the coil. * The light bulb does not shine since the magnet is moving at a constant speed. * The brightness of the light bulb is the same, regardless of the location of the magnet (as long as it is moving). Part D: Move the magnet through the coil very slowly, then at a moderate speed, and again very rapidly. QUESTION: How does the brightness of the light bulb change if the magnet is moved through the coil more quickly? Select one of these choices: * The bulb shines with the same brightness, but for a shorter duration * The bulb shines more brightly * The bulb shines less brightly. Part E: Select the Transformer tab, which contains an electromagnet at left (containing a DC battery) and a pickup coil attached to a light bulb at right. The electromagnet produces a magnetic field very similar to that of the bar magnet. Try to find a location where the stationary electromagnet (with a DC current) induces a current in the pickup coil and causes the light bulb to shine. QUESTION: Which of the following is correct? * There is no induced current in the coil, so the light bulb does not shine, if the electromagnet is stationary (for any location of the electromagnet) * The light bulb shines due to an induced current if one pole of the electromagnet is near the middle of the coil. * The light bulb shines due to an induced current if the electromagnet is inside the coil. Part F: Now, select an AC current source at top right (instead of the DC battery). You can adjust the frequency of oscillation of the current using the horizontal slider bar (in the blue AC Current Supply window), and you can adjust the peak current with the vertical slider bar. Place the electromagnet to the left of the pickup coil (as shown below).3966209372109 QUESTION: How does the average brightness of the light bulb depend on the AC frequency? Choose one answer: * The brightness remains the same when the frequency increases. * The brightness decreases when the frequency increases * The brightness increases when the frequency increases. Part G: With the electromagnet still situated just to the left of the pickup coil, turn the frequency all the way down to its lowest setting (5%). Watch how the brightness changes in time and how it correlates with the instantaneous current (which is shown by the position of the red vertical line in the AC current supply meter graph). QUESTION: When is the brightness the greatest? * When the current is zero * When the current is a maximum * The brightness doesn’t change with time! * When the current is a minimum Part H: Adjust the frequency to 100% so the bulb is always “on.” QUESTION: With the electromagnet still just to the left of the pickup coil, how does the average brightness of the light bulb depend on the number of loops of the pickup coil? (You can change the number of loops in the Pickup Coil properties box at bottom right.) * The brightness increases when the number of loops...