Download Benchmark Review Spring 2015 Electrostatics Protons have what

Benchmark Review
Spring 2015
Electrostatics
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Protons have what type of charge?
positive
Electrons have what type of charge?
negative
What is a charged atom called? ion
An object becomes positively charged when it _loses____ electrons and negatively charged when
it __gains___ electrons.
Charge is conserved. What does this mean?
Can’t be created or destroyed-transferred only
Like charges _repel_____, and unlike charges _attract____.
According to Coulomb’s Law, as the distance between two charges is halved, the electric force is
__quadrupled_____.
Is electric force a vector or scalar quantity?
vector
Which force is stronger; electrostatic force or gravitational force?electrostatic
What is the SI unit for charge? coulomb
What is the SI unit for electric potential difference?voltage
What is the SI unit for electric field strength?N/C
What is the name of the device used to detect electric charges? electroscope
Touching an object to Earth to eliminate excess charge is called what?grounding
Charging an object due to direct contact between the objects is called charging by
_conduction____.
Charging an object without any direct contact between objects is called charging by
_induction____.
A charged balloon will stick to a wall due to polarization____of charges.
A negatively charged balloon attracts another balloon. What conclusion can be drawn about the
2nd balloon? Positive or neutral
A material that allows electrons to flow freely throughout the material is called a
_condcutor____.
A force of 14 N exists on a charge which is 2.1 x 10-9 C. What is the magnitude of the electric
field? 6.7 x 109 N/C
21. A proton and electron are held 1 m apart and then released. What happens to the force between
them? Decreases In what direction will they accelerate? Toward each other
22. Give three examples of static electricity. Socks on carpet, lightning
23. Do electric field lines point toward or away from negative charges? Toward negative and away
from positive
24. Name two materials that are good insulators.
Plastic and wood
25. A plastic tube charged with wool will acquire what charge? negative
26. Lightning forms when the charges within the cloud become separated. In what region of the
cloud are the negative charges located? Negative at bootom
27. A 4.5 x 109 C charge is located 3.2 m from a 2.8 x 109 C charge. Find the magnitude of the
electrostatic force between the two charges. 1.1 x 1028N
28. What is the electric field 35 m from a charge of 3.0 C? 2.2 x 107 N/C
29. A charge gains potential energy as it is moved through an electric field because _work___ is done
on it.
Current Electricity
1.
What is the formula for Ohm’s Law?
V=IR
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
What is the formula for Electrical Power? P=IV
The amount of charge that flows through a circuit is called the _current____.
The SI unit for resistance is the _ohm____.
Current is measured with what unit?amperes
Current is directly related to voltage___ and inversely related to __resistance___.
A circuit consisting of only one path is what type?series
In what type of circuit will all lights go out if one goes out? series
What variable is the same everywhere in a parallel circuit? voltage
What variable is the same everywhere in a series circuit? current
In what type of circuit is the total resistance smaller than any single resistor in the circuit?
parallel
Name three factors that affect the resistance of a wire. Temperature, length, diameter
As temperature increases, resistance __increases___.
As length increases, resistance __increases___.
A 100 W light bulb is connected to a 120 V electric line. What is the current that the light bulb
draws? 0.83 A
What is the effect on the current in a simple circuit if both the voltage and the resistance are
reduced by half? Stays the same
How much electric energy is delivered to a 60 W light bulb if the bulb is left on for 2.5
hours?0.15 kwh
What is the equivalent resistance of a 3 ohm, 12 ohm, and 4 ohm resistor wired in series? 19 ohm
In what type of circuit does the current increase as more devices are added? parallel
A lamp is connected to a battery of 50 V, and the current that flows through the circuit is 2 A.
What is the resistance of the lamp?
25 ohms
A 2 ohm and 5 ohm resistor are connected in parallel to each other and in series with a 10 V
battery. What is the current through the 5 ohm resistor? 2 A
Three identical resistors are connected in series to a 9 V battery. What is the voltage drop
across each resistor?
3V
A 4 Ω and 2 Ω resistor connected in parallel are connected in series to a 12 V battery. What is
the voltage across the 4 Ω resistor? 12V
What device is used to measure the current flowing in a circuit? ammeter
Nina connects eight 12 ohm lamps in series. What is the total resistance? 96 ohms
In circuit 1, two identical light bulbs are connected in parallel to each other and in series
with a 12 V battery. In circuit 2, the same two light bulbs are connected in series with the
12 V battery. Which circuit produces more light?circuit one
In a parallel circuit, what happens to the current in the remaining bulbs when one bulb is
removed? No change
What is the equivalent resistance of a 30 ohm and a 20 ohm resistor connected in parallel? 12
ohms
How much voltage is required to make 4 A flow through a 12 ohm resistor? 48 V
A battery does 18 J of work on 10 C of charge. What voltage does the battery supply? 1.8 V
A 35 ohm, 55 ohm, and 85 ohm resistor are connected in parallel. The resistors are connected to a
35 V battery.
a. What is the equivalent resistance of the parallel combination? 17 ohms
b. What is the current through each resistor? 1 A thru 35 ohm; 0.64 A thru 55 ohm; 0.41 A
thru 85 ohm
Waves
1. What type of energy can be carried by a wave through the space?
2. Define wave.
3. What is the source of all waves? vibration
4. Waves transfer _energy____.
5. The only way to change the speed of a wave is to change its _medium_________.
6. What is the height of the wave from its equilibrium position? amplitude
7. Where can electromagnetic waves travel but mechanical waves cannot? vacuum
8. How far a wave travels in one second is the wave’s __wavelength________.
9. The number of vibrations per second is a wave’s ___frequency______________.
10. If the frequency of a wave is cut in half, what happens to wavelength?
doubles
11. What kind of wave does not appear to be moving? standing
12. If the speed of wave remains constant and the wavelength is tripled, what happens to frequency?
1/3
13. What is the relationship between frequency and wavelength? inverse
14. In which type of wave do particles move parallel to the direction in which the wave is traveling?
longitudinal
15. A light wave strikes a mirror at an angle of 600. What will be the angle of reflection? 30o
16.
a. Which two waves have the same wavelength?__A
and B____
b. Which two waves have the same amplitude?_B
and C______
c. Which wave has the most energy?__A____
d. Which wave has the highest frequency?_C_____
e.
What kind of interference is occurring between waves A and D? destructive
f.
What kind of interference is occurring between waves A and B? constructive
17. What is the wavelength of a 512 Hz sound wave traveling at 343.5 m/s? 0.67 m
18. A dolphin produces a sound with a frequency of 261.6 Hz. What is the period of the sound wave?
0.0038 s
19. You dip your finger in a pail of water 15 times in 6 seconds producing wave crests separated by
0.03 m. What is the frequency? What is the period? What is the velocity?
Frequency:____2.5 hz______________________
Period:______0.4 s_______________________
Velocity:___0.075 m/s_________________________
Sound
1. Sound waves are __longitudinal, mechanical________________waves and have areas of high
pressure called __compressions____________and areas of low pressure called
___rarefactions_________________.
2. Which travels faster, light or sound? Justify your answer. light
3. All mechanical waves, including sound, are produced by _vibrations_______________________.
4. Sound travels fastest in what state of matter? solid
5. A sound wave is a __mechanical_______________________________wave.
6. Sound waves cannot travel in a __vacuum_________________.
7. The speed of a sound wave depends on _temperature_____________________________.
8. As the temperature increases, the speed of sound _increases___________________.
9. For every 10 dB increase in the volume of sound, the intensity will increase by ___10______.
10. Write 3 equations used to calculate the speed of sound. V=d/t, v=frequency x wavelength,
v = 331 + 0.6(T)
11. Humans can hear frequencies between ____20___________and _______20, 000_____Hertz.
12. Sound waves having a frequency below 20 Hz are called
_infrasonic_________________________.
13. Sound waves with frequencies above 20,000 Hz are called ___ultrasonic___________________.
14. The perceived change in frequency due to the movement of the source of the wave is referred to
as the ___doppler effect___________________ ________________________.
15. Pitch refers to the __frequency____________________of the wave and the loudness refers to the
__amplitude____________________of the wave.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
The quality of sound is called __timbre____________________.
As the wavelength of sound increases, the pitch _decreases_____________________.
An echo is an example of the ____reflection_________________of a sound wave.
Resonance occurs when a ___standing wave_______________________wave is produced.
During closed pipe resonance, the standing wave that is produced will have a
__node____________ at one end of the pipe and an ___antinode______________________at the
other.
During open pipe resonance, the standing wave that is produced will have a(n)
__antidnode__________ at one end of the pipe and a(n) _antinode____________________at the
other end.
Differences in air temperatures results in the __refraction____________________of sound
waves.
Define natural frequency. Frequency at which an object vibrates
List the units used to measure the following quantities: pitch, sound intensity, wavelength, and
velocity. Pitch = Hz, intensity = dB, wavelength = m, velocity = m/s
Multiple resonances along a standing wave occur at what portion of a wavelength (spacing)?
½ wavelengths
Light
1. What type of wave is a light wave? electromagnetic
2. What is the speed of light in a vacuum? 3.0 x 108 m/s
3. Name three behaviors of light. Refraction, reflection, and diffraction
4. Give an example of a luminous object. Light bulb
5. Give an example of an illuminated object. moon
6. What does the term transparent mean? All Light is transmitted through
7. Name 2 objects that are translucent. Tissue paper, plastic
8. What does the term opaque mean? All light is reflected
9. Name the types of electromagnetic radiation in increasing energy. Radio, microwave, infrared
visible (ROYGBIV), ultraviolet, x-rays, gamma
10. What are the colors of visible light? ROYGBIV
11. Name the complimentary colors of light? Magenta and green, cyan and red, yellow and blue
12. How is white light formed? All three primary colors mix
13. Name the primary and secondary pigment colors. Primary pigment are magenta, yellow, and
cyan; secondary pigment colors are green, red and blue
14. What are complimentary colors? Magenta and green, cyan and red, yellow and blue
15. When red and blue light shine on a white sheet, the resulting color is
__magenta______________.
16. When red and green light shine on a white sheet, the resulting color is
__yellow________________.
17. What does it mean that light is polarized? All light is in one direction (some light is absorbed by a
filter)
18. Light reflected from a lake surface is polarized ___horizontally___.
19. In order for sunglasses to be effective in reducing glare produced from a road, the lasses should
be polarized __vertically__.
Magnestism
1.
2.
3.
4.
5.
The ends of a magnet are called _poles__________.
Name three elements that can be permanently magnetized. Nickel, cobalt, and iron
Like poles _repel____ and opposite poles __attract_____.
A piece of iron can be magnetized if the _domains__________ are aligned.
Draw a magnet and sketch the field lines. Exit from one pole, circle the magent and enter
the opposite pole
6. The strength of a magnetic field increases with __decreasing___________ distance.