1. "The sum of the emf's and potential differences around a closed loop equals zero" is a consequence of:
 A. Newton's third law
 B. Ohm's law
 C. Newton's second law
 D. conservation of energy
 E. conservation of charge

2.

A portion of a circuit is shown, with the values of the currents given for some branches. What is the direction and value of the current i?

 A. ¯, 6A
 B. ­, 6A
 C. ¯, 4A
 D. ­, 4A
 E. ¯, 2A

3. A battery is connected across a parallel combination of two identical resistors. If the potential difference across the terminals is V and the current in the battery is i, then:
 A. the potential difference across each resistor is V and the current in each resistor is i
 B. the potential difference across each resistor is V/2 and the current in each resistor is i/2
 C. the potential difference across each resistor is V and the current in each resistor is i/2
 D. the potential difference across each resistor is V/2 and the current in each resistor is i
 E. none of the above are true

4. A total resistance of 3.0 W is to be produced by combining an unknown resistor R with a 12 W resistor. What is the value of R and how is it to be connected to the 12 W resistor?
 A. 4.0 W, parallel
 B. 4.0 W, series
 C. 2.4 W, parallel
 D. 2.4 W, series
 E. 9.0 W, series

5. Four 20-W resistors are connected in series and the combination is connected to a 20-V emf device. The potential difference across any one of the resistors is:
 A. 1 V
 B. 4 V
 C. 5 V
 D. 20 V
 E. 80 V

6.

Each of the resistors in the diagram is 12 W. The resistance of the entire circuit is:

 A. 5.76 W
 B. 25 W
 C. 48 W
 D. 120 W
 E. none of these

7. Two identical batteries, each with an emf of 18 V and an internal resistance of 1 W, are wired in parallel by connecting their positive terminals together and connecting their negative terminals together. The combination is then wired across a 4-W resistor. The potential difference across the 4-W resistor is:
 A. 4.0 V
 B. 8.0 V
 C. 14 V
 D. 16 V
 E. 29 V

8. A 120-V power line is protected by a 15-A fuse. What is the maximum number of "120 V, 500 W" light bulbs that can be operated at full brightness from this line?
 A. 1
 B. 2
 C. 3
 D. 4
 E. 5

9.

Suppose the current charging a capacitor is kept constant. Which graph below correctly gives the potential difference V across the capacitor as a function of time?

 A. I
 B. II
 C. III
 D. IV
 E. V

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