Self-Test: Electric Circuits Test #2
Suggested Time: 65 minutes

Which of the following diagrams shows an ammeter correctly placed to measure the circuit current and a voltmeter correctly placed to measure the potential difference across the battery?

2. What is the current through the 10 W resistor in the circuit shown below?



0.11 A B. 0.37 A C. 1.2 A D. 1.7 A

Current is a measure of

A. the number of charges stored in a cell.

B. the amount of energy given to a charged object.

C. the charge passing a point in a circuit in a given time.

D. the resistance to the flow of charged particles in a circuit.

4. The battery in the diagram below is delivering a current of 2.0 A.

What will be the reading on a voltmeter connected to the battery terminals?

A. 1.0 V B. 5.0 V C. 6.0 V C. 6.0 V
5. What is the total power dissipated by the three resistors in the circuit shown below? 


A. 12 W B. 16 W C. 23 W C. 30 W



Which of the following combinations of three identical resistors has the least equivalent resistance?


An electrical device with a constant resistance draws 0.75 A when connected to a 4.8 V source. What are the current and power for this device when it is connected to a 6.0 V source?



8. Which of the following graphs illustrates Ohm’s law? 

9. In the following circuit, what is the terminal voltage of the battery? 


A. 6.9 V B. 7.0 V C. 8.0 V D. 9.0 V

Which of the following arrangements would draw the largest current when connected to the same potential difference? All resistors have the same value.



11. Find the current flowing through resistor R2 in the circuit shown below. 


A. 1.5 A B. 2.5 A C. 3.5 A D. 5.0 A

A 120 V supply is connected to a heater of resistance 15 W. What must the resistance of another heater be in order to produce the same power output when connected to a 240 V supply?

A. 3.8 ohms B. 7.5 ohms C. 30 ohms D. 60 ohms

In circuit one, resistors and voltmeters are connected as shown. In circuit two, an additional resistor R4 is placed in parallel with resistor R2.

How have the values of V1 and V2 in circuit two changed compared to those in circuit one?



If switch S is opened, how does the brightness of each bulb (X, Y, and Z) compare to the situation when the switch was closed?



15. A current of 1.50 A flows through the 40.0 W resistor.

What is the potential difference of the power supply? (7 marks)


16. Two identical light bulbs, wired in parallel to a battery, are equally bright. When one of the bulbs burns out, however, the other bulb is observed to glow brighter. Using principles of physics, explain why the battery causes the remaining bulb to glow more brightly. (4 marks)
17. What is the power dissipated in the 8.0 W resistor in the circuit as shown? (7 marks) 


18. The graph shows the light energy EL emitted by a bulb versus time t.  

a) Find the power output of the bulb. (2 marks)

b) If this bulb is 20% efficient, find the power delivered to the bulb. (3 marks)


19. In the circuit below, resistor R1 dissipates 0.40 W. Resistors R2 and R3 are identical. 

What is the resistance of R2? (7 marks)


20. The current through the 50.0 W resistor in the circuit below is 0.14 A

a) Determine the emf of the battery. (5 marks)

b) Determine the power dissipated in the battery’s internal resistance. (2 marks)

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