Physics 108 Quiz #2 Experiment: DC Circuit Spring 2015 Name: TA: Day/Time: Section: 1. Three identical lightbulbs with resistance R are connected as shown in the circuit below. The circuit also contains an open switch. If the switch is closed what will happen to the intensity of bulb 1 and 2. (3pts) i) bulb 1 gets brighter and bulb 2 gets dimmer ii) bulb 1 gets dimmer and bulb 2 gets brighter iii) no change iv) both become brighter 1 v) both become dimmer Ans:( i )(total resistance will decrease hence total current will increase) 2 V 2. Each of the resistors in the diagram below has a resistance of 12 . The resistance of the entire circuit is: (5pts) (please show your work clearly to get partial credit) i) 1.4 ii) 10 iii) 60 iv) 12 v) None of these Ans: (ii) (12/3+12/2= 10 ) 3 3. Consider the circuit shown below. A. What is the equivalent resistance of this circuit? (5 pts) B. Solve for the total current ( I ) in the circuit (3 pts) (show your work clearly) Ans: A. Equivalent resistance= 9.5 B. Total current =12/9.5= 1.26 A I 2