Download Physics 2010

NAME: ___________________________________________________________
PERIOD: __________
LAB EC – 2 CIRCUIT SCHEMATICS
GO TO: http://www.physicsclassroom.com/Class/circuits/u9l4a.cfm
Read through information and example problems. Answer all
questions on this paper, and then check you solutions with Physics
Classroom.
1. Use circuit symbols to construct schematic diagrams for the following circuits:
A. A single cell, light bulb and switch are placed together in a circuit such that the switch
can be opened and closed to turn the light bulb on.
B. A three-pack of D-cells is placed in a circuit to power a flashlight bulb.
C.
D.
2. Use the concept of conventional current to draw an unbroken line on the schematic
diagram at the right that indicates the direction of the conventional current. Place an
arrowhead on your unbroken line.
Select Next Section: Two Types of Connections
Read Information and Example Problems.
Answer the questions on the paper and check your answers with Physics Classroom.
1. Observe the electrical wiring below. Indicate whether the connections are series or
parallel connections. Explain each choice.
2. Two electric circuits are diagrammed below. For each circuit, indicate which two devices
are connected in series and which two devices are connected in parallel.
In series? ___________________ In series? ___________________
In parallel? _________________ In parallel? _________________
Select Next Section: Series Circuits
Read Information and Example Problems.
Answer the questions on the paper and check your answers with Physics Classroom.
1. Use your understanding of equivalent resistance to complete the following statements
A. Two 3- resistors placed in series would provide a resistance that is equivalent to one
_____- resistor.
B. Three 3- resistors placed in series would provide a resistance that is equivalent to one
_____- resistor.
C. Three 5- resistors placed in series would provide a resistance that is equivalent to one
_____- resistor.
D. Three resistors with resistance values of 2- , 4- , and 6- are placed in series. These
would provide a resistance that is equivalent to one _____- resistor.
E. Three resistors with resistance values of 5- , 6- , and 7- are placed in series. These
would provide a resistance that is equivalent to one _____- resistor.
F. Three resistors with resistance values of 12- , 3- , and 21- are placed in series. These
would provide a resistance that is equivalent to one _____- resistor.
2. As the number of resistors in a series circuit increases, the overall resistance (increases,
decreases, remains the same) and the current in the circuit (increases, decreases, remains
the same).
4. Three identical light bulbs are connected to a D-cell as shown at the right. Which one of
the following statements is true?
A. All three bulbs will have the same brightness.
B. The bulb between X and Y will be the brightest.
C. The bulb between Y and Z will be the brightest.
D. The bulb between Z and the battery will be the brightest
8. A 12-V battery, a 12-ohm resistor and a light bulb are connected as shown in circuit X
below. A 6-ohm resistor is added to the 12-ohm resistor and bulb to create circuit Y as
shown. The bulb will appear ____.
A. a. dimmer in circuit X
B. b. dimmer in circuit Y
C. c. the same brightness in both circuits
Select Next Section: Parallel Circuits
Read Information and Example Problems.
Answer the questions on the paper and check your answers with Physics Classroom.
1. As more and more resistors are added in parallel to a circuit, the equivalent resistance of
the circuit (increases, decreases) and the total current of the circuit (increases, decreases).
4. Three identical light bulbs are connected to a D-cell as shown below. P, Q, X, Y and Z
represent locations along the circuit. Which one of the following statements is true?
A.
B.
C.
D.
E.
F.
The current at Y is greater than the current at Q.
The current at Y is greater than the current at P.
The current at Y is greater than the current at Z.
The current at P is greater than the current at Q.
The current at Q is greater than the current at P.
The current is the same at all locations.
8. Use your understanding of equivalent resistance to complete the following statements:
A. Two 6- resistors placed in parallel would provide a resistance that is equivalent to one
_____- resistor.
B. Three 6- resistors placed in parallel would provide a resistance that is equivalent to one
_____- resistor.
C. Three 8- resistors placed in parallel would provide a resistance that is equivalent to one
_____- resistor.
D. Three resistors with resistance values of 2- , 4- , and 6- are placed in parallel. These
would provide a resistance that is equivalent to one _____- resistor.
E. Three resistors with resistance values of 5- , 6- , and 7- are placed in parallel. These
would provide a resistance that is equivalent to one _____- resistor.
F. Three resistors with resistance values of 12- , 6- , and 21- are placed in parallel.
These would provide a resistance that is equivalent to one _____- resistor.
9. The overall or equivalent resistance of three resistors placed in parallel will be _____.
A.
B.
C.
D.
greater than the resistance of the biggest R value of the three.
less than the resistance of the smallest R value of the three.
somewhere in between the smallest R and the biggest R value of the three.
nonsense! No such generalization can be made. The results vary.