Lab Manual PHY-1570 (College Physics II) Summer - 2023 Ammeter 0-5A Power Supply Fig 1 Connecting the Power Supply and Ammeter For Your Report For each of the cases make a plot of I. Force (y-axis) vs. length (x-axis), II. Force vs. number of magnets, III. Force vs. number of magnets reversed, and IV. Force vs. current. Part I From the plot for part I, calculate an experimental value for the magnetic field strength. Also, from the linear fit to your data, determine the length of loop #39.Name: Maria Bogan 7-Magnetic Force Introduction A current-carrying wire in a magnetic field experiences a force that is usually referred to as a magnetic force. The magnitude of this force depends on four variables: the magnitude of the current (D); the length of the wire (Z); the strength of the magnetic field (B); and the angle between the field and the wire (0). The magnetic force can be described mathematically by the equation Fm = ILBsine. (1) For our experiments the angle between the wire and the magnetic field will be 90, thus we get Fm = ILB. (2) To verify this expression, we are going to conduct three experiments in which force will be measured as a function of current, wire length and magnetic field strength. Procedure To begin, set up the circuit as in figure 1. You will use the power supply in current mode. With the power supply OFF, turn the voltage, and current knobs to their minimum values (all the way counterclockwise). Then turn the voltage knobs to their maximum (all the way clockwise). The red LED between the two current knobs should be illuminated. The current knobs can now be turned to adjust the current to the desired value and the power supply will do its best to maintain that value. For the first two parts of the experiment choose a current of 0.5 A. Make sure your ammeter is set to amps NOT milliamps (Channel and knob!!) Before proceeding, have the instructor check your circuit. Part I - Force verses Length of Wire 1. Insert a current loop into the ends of the main unit. Place the magnet assembly on the pan of the balance. Slide the current loop into position between the poles of the magnet, ensuring that the loop does not touch the magnets when in its final position. With no current flowing, zero the balance. 2. Now turn the current on (0.5 A). Record the mass value and current reading in Table 1. (Don't forget to mark down which current loop you are using!) Loop Number Length (cm) 37 2.2 022 me 38 4.2 . 042 m 39 3.2 ? . 032 mix 40 1.2 . 0 12 m 41 6.4 064 m 42 8.4 1084 m3. Turn the current off, remove the current loop and replace it with a different leng Repeat the above steps with the new loop in place. 4. Turn the current off, remove the current loop and replace it with a different length loop. Repeat the above steps with the new loop in place. 5. Repeat the above procedures for the remaining four loops. 6. Notice that the length of loop number 39 has not been included. You will determine the length of this loop from your results. See "For Your Report" section. Part II - Force verses Magnetic Field Strength In this part of the experiment, we will be removing the individual magnets from the magnet assembly to alter the magnetic field strength. 1. With a current loop in place (don't forget to mark down which loop is used), make a measurement of the current and mass. Enter these values in Table 2. 2. Turn off the current, carefully take the magnet assembly off the balance and remove one of the magnets. Replace the assembly on the balance and repeat the above measurement. Repeat the above steps until there is only one magnet left. ((What will be the force on the wire when the number of magnets is equal to zero?) Part III - Reversing Magnets Repeat part II but reverse the direction of the magnets, placing them back on the assembly one at a time, instead of removing them (put red ends next to white ends) until all magnets have changed their orientation by 180. Discuss your results. Part IV - Force verses Current 1. Set up the magnet assembly (replace all of the magnets) and current loop as previously. Zero the balance with the current off. 2. Turn the current to 0.25 A and quickly make a reading of the force. The circuit is not very stable so be cautious when making your measurements. You may need to fine tune the current knob to get it to remain somewhat constant. Record your reading in Table 4. 3. Increase the current by 0.25 A steps, reading the balance each time, up to a maximum value of 3 A. Record your data in Table 4. Table 1 2: 100 m 2 1000 Loop # Wire Length Current (A) Mass (kg) Force (N) 37 2 2cm = . 022 m|0. 5) A 158583 Ka 38 42 cm = 042 m 0.51 A 158644 ka 39 3.2 cm = 032 m 0.53 A 1 15843 Kx 40 1.2 cm = 012 m|0. 51 A 1 158576 Ka 14.4 cm = . 064m 10. 50 A 158541 Ka 42 184 cm= 084m | 0. 50 A .1 68771 Ka Experimental value for the length of loop #39 = Loop # = 3 Wire Length = _2:2 cm (: 022 m) Table 2Lab Manual PHY-1570 (College Physics II) Summer - 2023 2 1000 for (kq) from ( g ) (37) # of Magnets Current (A) Mass (kg) Force (N) LOOP 6 0 . 50 A .158461 / ka 5 0 50 A . 144955 Ka 4 D : 50 A 13509 Ka 3 0 .50 A 1. 1234 32 ka 2 O . 50 A .141744 ka 1 . 50 A 099833 ka 0 O . 50 A . 0879 98 kq Loop # = 137 Wire Length = 2.2 cm (.022 m) Table 3 1000 # of Magnets Reversed Current (A) Mass (kg) Force (N) 0 O.5 A . 08792 ka 1 O.S A . 099812 Ka 2 0.5 A .1 439 ka 3 05 A . 123082 kq 4 DIS A . 134722 . kq 5 O. S A 6 0 . 5 A . 15848 kq Loop # = 371 Wire Length = 2.2 cmi ( . 022 m ) Table 4 -1000 Current (A) Mass (kg) Force (N) 0.25 00033 Ka 0.5 00 00 4 7 Ka 0.75 . 0000 99 Ka 1.0 .0001 31 Ka 1.25 .00 0 142 kg 1.5 000 1960 Ka 1.75 . 090 227 ka 2.0 000 259 kq 2.25 . 000 293 Kq 2.5 . 000 324 kq 2.75 . 000 354 Kq 3.0 .0003 88 K