Part 1: Charging and Discharging a Capacitor Figure 4 A B We are going to study the RC circuit shown in Figure 4 which consists of a 100 0 resistor connected in series to a 4700 uF capacitor (1uF = 10 6 F ), a switch which is assumed to be closed at t= 0 and two D batteries (1.5 V each) connected head C 4.7 mF to tail with the total voltage & = &1 + E2. The & (or Vmax) can actually be less than 3.0 V, so let's first check what is the B+ A maximum voltage across the two batteries. Y = By using 4" jumper cables make the following connections a-A, Q-8 and y-B, Ez then by using 12" jumper cable make connection between B and R. 100 0 = Connect the red terminal of the voltage sensor into B and black terminal into 8. W R = Click "Record" and close the switch by pushing down on the button, and continue to hold the button down for ~ 3-5 seconds. Then, click "Stop" and release the button. The voltage across the batteries should now be visible. = Click "Data Highlighter" to select the data points and then "Statistics Tool" _ to find the average value of the Vmax. Record its value below. Vmax 2.823 () RC Circuits Page 3 of 10Charging a Capacitor - Detach the voltage sensor and B-R jumper cable, and connect this jumper cable between B and U. - Take the 46" red cable and attach one end into the current sensor's red socket and plug its second terminal into V on the circuit board, then take the 46" orange cable and attach one end into the current sensor's black socket and plug its second terminal into R on the circuit board. Connect the Voltage sensor across the capacitor by plugging the red terminal into U and black terminal into V (see Figure 4 for details) 1.1. Let's make some predictions before conducting the experiment by knowing that & = Vmax, VR(t) = "Predicted" I(t) . R and Q(t) = C . Vc(t). Compute the values listed in Table 1 and record them in the column called 470 0 uf x . Table 1 Value Predicted Measured The time constant, t (in sec.) 0. 48 ks The voltage drop across the capacitor immediately after the switch is closed at t= 0, Vat=o (in V) 0. 014 V The charge on the capacitor immediately after the switch is closed at &= 0 s, Qt=0 (in coulombs) 6.58 x 10 -5 The voltage drop across the capacitor 1 second after the switch is closed, Vat=1 (in V) 2. 493 The charge on the capacitor 1 second after the switch is closed, Qtel (in coulombs) 0 , 01 17 The voltage drop across the capacitor after the switch is closed 2.859 for a long time (t-> co), VC,t-10. (in V) The maximum charge stored on the capacitor after the switch is closed for a long time (t- 0o), et-20. = emax (in coulombs) 0. 0 1 3 4 3 The current flowing through the circuit immediately after the switch is closed at t= 0, It=0 = Imax (in A) 0 , 026A 1.5. Use The current flowing through the circuit 1 second after the switch is closed, It= (in A) 0.004 1.6. Use The voltage drop across the resistor immediately after the 2.560 switch is closed at t= 0, VR,t=0 (in V) The voltage drop across the resistor after the switch is closed 0.005 for a long time (t-> co), VR,t-.. (in V) 1.2. Show your work for the following calculations of the Vc,t=1, It=1, et=1 and Qt-zoo. , FET B(t-to)) ) + C" his e constant and its unce uned by the curve-fitting procedure and RC Circuits Page