Multiple Choice

1) As the temperature of a coil of copper wire increases, its electrical resistance
a) Increases b) decreases c) remains the same

2) Which graph represents a circuit element at a constant temperature that obeys Ohm’s law

A B C D

3) The resistance of a wire at a constant temperature depends on the wire’s
a) length, only
b) type of metal, only
c) length , cross-sectional area, and type of metal
d) length and cross sectional area, only

4) The graph below represents the relationship between potential difference and current for four different resistors. Which resistor has the greatest resistance?

5) An Ampere-Volt is a unit of
a) work b) resistance c) energy d) power

6) Using the circuit below, determine the electrical energy expended in resistor R in 2.0 seconds.

a) 20. J b) 80 J c) 40 J d) 120 J

7) If the current in an electric circuit is halved and the resistance is doubled, the power will
a) remains the same
b) be doubled
c) be 8 times larger
d) be halved

8) In the circuit represented below, which switches must be closed to produce a current in the resistor?
a) 1 and 4 b) 2 and 3 c) 1,2 and 3 d) 2,3 and 4

9) A device which uses chemical energy to move charge in a circuit is called a:
a. Battery c. Ammeter
b. Voltmeter d. Potato-meter

10) If V2 in the diagram is 24 Volts, V1 will read
a) 8V b) 24V c) 48V d) 72V

Base your answers to 11-13 on the diagram below, which shows three resistors connected to a 15Volt source.

11) The equivalent resistance of the circuit is
a) 100 Ω b) 200 Ω c) 300 Ω d) 400 Ω

12) The total power developed by the circuit is
a) 0.25 W b) 0.50 W c) 0.75 W d) 1.0 W

13) If resistor R3 is removed and replaced by a resistor of lower value, the resistance of the circuit will
a) increase b) decrease c) remain the same

14) Which circuit segment has an equivalent resistance of 1.2 Ohms?

Base you answers for the next questions 15-17 on the diagram below, which shows a 40.W light-bulb and a 120 W light-bulb connected in parallel to a 120 V source.

15) What is the current in Bulb A
a) 4800 A b) 40 A c) 3.0 A d) 0.33 A

16) What is the potential difference across bulb B
a) 60.V b) 120 V c) 240 V d) 480 V

SHORT ANSWER: Show all your work for full credit.
1) Find the equivalent resistance of the below circuit.

2) A 20 Ω and a 5 Ω resistors are connected in parallel with a 16 Volt battery. Draw an accurate diagram of this circuit; calculate the equivalent resistance of the circuit and the amount of current flowing through each resistor

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