Circuit Review

1. When two light bulbs are connected in series

1. The same amount of current flows through each light bulb.

2. The current through each light bulb is proportional to the resistivity of the bulb.

3. The light bulbs will not work unless there is a fuse in the circuit.

4. There are at least two branches of the circuit.

2. When one light bulb burns out in a series circuit containing several light bulbs

…a. The other light bulbs burn more

brightlyb. Nothing changes in the rest of the

circuitc. None of the other bulbs will light up

3. When resistors are put in series, their overall resistance is

a. Larger than that of any individual resistor

b. The same as the resistance of one of the resistors

c. Smaller than the resistance of any of the resistors

4. When resistors are put in parallel, their overall resistance is

a. Larger than that of any individual resistor

b. The same as the resistance of one of the resistors

c. Smaller than the resistance of any of the resistors

5. A wire 5.0 m long and 3.0 mm in diameter has a resistance of 100. . A 15 V potential difference is applied across the wire. What is the current in the

wire?

V IR

I VR

15100

0.15A

6. Two appliances operate at the same voltage. Appliance A has a higher power rating then

appliance B. How does the resistance on A compare with that of B

1. A’s resistance is larger than B’s.2. A’s resistance is smaller than B’s3. A’s resistance is the same as B’s.

P V2

R

7. What is the resistance of a 100. W light bulb if it is plugged into a 120. V

outlet?

P V2

R

1001202

RR144

8. Three resistors with resistance of 6 , 12 , and 24 are connected in

series. What is the total resistance of the circuit?

Rtotal

61224 42

9. Three resistors with resistance of 6.0 , 12 , and 24 are connected in series with a 12V

battery. What is the current through the 12 resistor?

V IR1242II 0.29A

The current is the same through all

of them so the total resistance must

be used.

10. Which two resistors are in parallel with each other?

R2 and R3

11. Electrical resistance in a wire depends on the wire’s

1. Resistivity

2. Length

3. Cross sectional area

4. All of the above

12. As more identical resistors R are added to the parallel circuit shown, the total resistance

between points P and Q …

A. Increase

B. Stay the Same

C. Decrease …P Q

R

13. When one bulb is unscrewed, the other bulb will remain lit in which circuit…

A. Circuit 1

B. Circuit 2

C. Both

D. Neither

Circuit 1

Circuit 2

14. Charge flows through a light bulb. Suppose a wire is connected across the bulb as shown.

When the wire is connected…A. All the charge continues

to flow through the bulb, and the bulb stays lit.

B. Half the charge flows through the wire, the other half continues through the bulb.

C. Essentially all the charge flows through the wire and the bulb goes out.

D. None of these

15. When the series circuit shown is connected, Bulb A is brighter than Bulb B. If the positions of

the bulbs were reversed…

A. Bulb A would be brighter

B. Bulb B would be brighter

C. They would be of equal brightness

The bulbs are connected in series, so the same current passes through both of them. Different brightnesses indicate different filament resistances. Bulb A is NOT brighter because it is “first in line” for the current of the battery! After all, electrons deliver the energy, and they flow from negative to positive --- in the opposite direction!

16. Which bird is in trouble when the switch is closed?

A. Bird 1

B. Bird 2

C. Neither

D. Both

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