Review for Quarter 3 Test
____________________ 1. An object has a charge of -5.40C. How many excess electrons does it have?
2a. Draw a circuit with a 3Ω and a 6Ω resistor in parallel with each other and with a 9V battery. b. Draw the schematic of how to
measure the current through and the voltage across the 3Ω resistor. c. What is the current through and the voltage drop across the 3
ohm resistor?
3. A resistor uses 18W when 3A of current flow through it. When it is removed from the circuit and put in a new one it is found to be
getting 4A of current. How much power will it dissipate now? (Hint: You can NOT assume the voltage across it is the same as when
it got 3A.)
4. A variable (changeable) resistor uses 18W when 3A of current flow through it. If the voltage across it remains the same, how much
power will it dissipate when 4A of current flow through it?
5. Circle all of the following which are not actually true:
A. The wires in circuits have no resistance.
C. The resistance of a light bulb is always the same.
B. Electric circuits have electrons moving through the wires.
D. Ohm’s Law, V=IR is true for all types of resistors.
____________6. A man fishing on a boat feels the boat move up and down due to the ocean waves with a frequency of 0.60Hz. If he
estimates the distance between successive wave crests to be 6.0m, what is the wave speed of the ocean waves?
A. 0.20m/s
B. 1.8m/s
C. 3.6m/s
D. 5.0m/s
7.___________ All waves
a) transport energy from one point to another.
b) transport matter from one point to another.
c) transport both energy and matter from one point to another.
d) can only move through liquids and gases.
8. ________________________________A tuning fork has a frequency of 538Hz. If the speed of sound is 336 m/s where the tuning
fork is, what is the wavelength of the sound it makes?
9. Sketch the resultant of these two wave pulses when they
completely overlap each other.
Draw answer here:
10. What do sound waves need that light does not require?
11. Three resistors are wired in series with a battery. If a 4 th resistor is added in series will the power dissipated by the whole circuit
increase or decrease?
_____12. A balloon is positively charged by being rubbed on a pair of jeans. The balloon is then able to pick up small pieces of paper.
The paper is a. positive
b. negative
c. neutral (and unpolarized)
d. polarized
_____ 13. Differences between insulators and conductors include: a. insulators can’t be charged
b. insulators can’t be polarized
c. insulators can’t be charged by induction
d. B and C
e. none of the above
_____ 14. When a positively charged object is touched to “ground,”
a. protons move from the charged object into the ground.
c. electrons move from the ground into the charged object.
b. protons move from the ground into the charged object.
d. electrons move from the charged object into the ground.
15. What is the difference between refraction and diffraction?
_____ 16. Two resistors in series are connected to a battery. When third resistor is added is series with the first two, the voltage
across the first resistor
a. increases
b. decreases
c. stays the same
d. not enough info
_____ 17. Two resistors in parallel are connected to a battery. When third resistor is added is parallel with the first two, the voltage
across the first resistor
a. increases
b. decreases
c. stays the same
d. not enough info
_____ 18. Two charged particles qA and qB exert a force, F, on each other. What will the force be if the distance between the charges
is doubled and the charge of qA is doubled?
a. 2F
b. 8F
c. F/2
d. F
e. F/2
_____ 19. In the picture to the right, A is ____, B is ____, and ____ has the greater magnitude of charge.
a. negative, negative, A b. negative, negative, B
c. positive, negative, A d. positive, negative, B
e. positive, positive, A
f. positive, positive, B
A
B
_____ 20. The pictures below show a sequence of events between a negatively charged balloon and a conducting sphere sitting on top
of an insulator. AFTER the pictures below the hand is removed, and then the balloon is removed. Which of the answers below best
shows what the (excess) charge on the conducting sphere will look like now?
a.
b.
c.
d.
e.
+
+ –
–
– +
–
–
+
+
+
–
–
–
–
+
– +
A
D
C
+
–
+ –
Z
B
+
P
_____ 21. Charged particles P and Q have equal but opposite charges and the arrangement shown. Which
of the vectors most accurately shows the direction of the electric field at point Z?
-Q
22 Which of the following must be incorrect if the other 3 are correct (1 mistake in a & 1 in b):
a) The voltage drop across:
A: 1.34V
B: 1.42V
C: 1.37V
the batteries: 1.40V
b) The current through:
A: 0.06A
B: 0.06A
C: 0.12A
the batteries: 0.06A
23. (Solve on another sheet of paper) a. Find the equivalent resistance of the circuit shown.
b. Find the current through & the voltage drop across the 2.0Ω resistor.
24. What’s the net force on the middle particle? (Solve on another sheet of
paper.)
-67C
72 cm
__________________________________ 25. What is the magnitude and direction of the electric
field at B if the charges of A and C are –3.00C and +5.00C, respectively? (Solve on another
sheet of paper.)
+45C
92 cm
-83C
y
x
1.00mm
2.00mm
B
- A
+
C