4. The circuit in Fig. 8 consists a DC power supply with Is = 9 , an ammeter A, a voltmeter V, a lamp (L) of resistance R, , two resistors R, and R, along with two switches S, and S, SI R = 60 M mm Lamp R2 Vy = 9V Figure 8 Circuit diagram for question #4. There are 4 switch settings for S, and S, which affect the connections of the two resistors R, and R, in the circuit of Fig. 8. Switch setting (a): (S, open, S, open) At setting (a) the ammeter reading is 1 = 0.5 A and voltmeter reading is V, = 3 V. From these given data to find the resistance of R, = 2, R = Switch setting (b): (S, open, S, closed) Switch setting (c): (S, closed, S, closed) Switch setting (d): (S, closed, S, open) Work to be done: (1) Draw circuit diagram for each of above 4 switch settings. (2) From each diagram to calculate the quantities listed in Table 7. Where VL, I, and P, are the voltage, current and power for the lamp; I, & Ps are the current and power for the source. (3) Compare the lamp brightness based on the values of Pr (W) (power dissipated in the lamp). Table 7 Calculated VL, It, PL, Is, P, and comparison of brightness of the lamp at 4 switch settings. Switch setting VI (V) I, ( A) P, (W ) IS (A) PS (W) Lamp brightness (a) (S, open, S, open) (b) (S, open, S, closed) (c) (S, closed, S, closed) (d) (S, closed, S, open) 30