Ch 10-12 Physics
If an atom starts with a charge of 11 protons, 12 neutrons, and 11 electrons and loses 2 electrons, what is its charge?
+2
An atom with 15 protons and 15 electrons gains 3 electrons to become an ion. What is its charge?
-3
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected in series with a 5.0 V battery. The internal resistance of the battery is negligible. What is the current through R1?
.24 A
An i Pod draws about 3.7 volts (i Pod batteries are rated for 3.7 volts and 1200 mAhours.) Ignore the internal resistance of the battery. If the i Pod has a resistance of 12 ohms, what is the current through the i Pod?
.31A
The potential difference across the terminals of a storage battery not connected in any circuit is observed to be 12 V. When it is connected to an external resistance the potential difference across the terminals is observed to be 11 V while the current in the external resistance is 2 A. What is the internal resistance of the battery?
.5 ohms
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected in series with a 5.0 V battery. The internal resistance of the battery is negligible. What is the voltage drop in R1
.71 V
A 12 ohm resistor and a 24 ohm resistor are connected in series in a circuit with a 6.0 volt battery. Assuming negligible internal resistance in the battery, the current in the 12 ohm resistor will be
0.167 A.
Two equal charges repel one another with a force of 4.0 x 10-4 N when they are 10 cm apart. If they are moved until the separation is 20 cm, the repulsive force will be
1.0 x 10-4N.
A series circuit has a 6.70 volt source and a 2.00 ohm resistance and a 4.00 ohm resistance. What is the total current flow, in amps?
1.12
An iPod draws about 3.7 volts (iPod batteries are rated for 3.7 volts and 1200 mAhours.) Ignore the internal resistance of the battery. If the iPod has a resistance of 12 ohms, what is the POWER through the iPod?
1.14 watts
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected inseries with a 5.0 V battery. The internal resistance of the battery is negligible. What is the power of the system?
1.19 W
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected in parallel with a 5.0 V battery. The internal resistance of the battery is negligible. What is the current through R1?
1.67 A
A 5.0-ohm resistor has a current of 2.0 amps through it. What is the voltage across it?
10 V
A current with 12 amps flows from a hair drier for 3.0 seconds from a 120 Volt source. What is the resistance of the hair drier?
10 ohm
A light bulb with a resistance of 3 ohms has a voltage difference of 6 V across its leads. What is the power drawn by the bulb?
12 W
A 10 ohms, 22 ohms, and 100 ohms resistor are hooked in series. What is the total resistance?
132 ohms
A current with 12 amps flows from a hair drier for 3.0 seconds from a 120 Volt source. What is the power of the hair drier?
1440 W
A heater is rated to dissipate 1800 W when connected to a 120 V source. The current drawn by the device is
15 A
Resistors of 5 ohms, 4 ohms, and 6 ohms are connected in series. What is the total or equivalent resistance of these three?
15 ohms
A household circuit rated at 120 Volts is protected by a fuse rated at 15 amps. What is the maximum number of 100 watt light bulbs which can be lit simultaneously in parallel in this circuit without blowing the fuse?
18
A certain kind of light bulb carries 1.5 amperes of current when connected to a 120 Volt AC circuit. What is its power rating?
180 W
A light bulb with a resistance of 3.0 ohms has a voltage difference of 6.0 V across its leads. What is the current through the bulb?
2 amps
Resistors of 5 ohms and 4 ohms are connected in parallel. What is the equivalent resistance when connected in this way?
2.2 ohms
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected in parallel with a 5.0 V battery. The internal resistance of the battery is negligible. What is the current through the circuit (total current)?
2.78 A
Three different size lights are running off a low voltage system. The resistance of the three lights are R1 =3 ohms, R2 = 9 ohms, and R3 = 9 ohms. They are all connected in parallel with a 5.0 V battery. The internal resistance of the battery is negligible. What is the voltage across R3?
5V
A parallel circuit has a 8.10 volt source and a 2.00 ohm resistance and a 4.00 ohm resistance. What is the total current flow, in amps?
6.08
A 10 ohms, 22 ohms, and 100 ohms resistor are hooked in parallel. What is the total resistance?
6.4 ohms
27 coulombs of charge flows through a hair dryer every 3.0 seconds. What is the current flow?
9A
Who named the charges positive and negative.
Ben Franklin
____ showed that lightning was a form of electricity.
Ben Franklin
A 1.5 V flashlight battery, a 10 ohm resistor, and a flash light lamp are available. How should the lamp be connected in a circuit so that it would glow the brightest?
Connect it directly to the battery; don't use the resistor.
The voltage of a battery is the
Energy supplied per coulomb of charge or work done per unit charge for the output by the battery
A small bit of paper is electrically neutral. A charged rod can attract the bit of paper by the process of ________
Polarization
Why is it unlikely that cell phones present a health danger?
Radio waves are long wavelength and therefore low energy. They are considered non-ionizing radiation.
When you receive a charge by TOUCHING a positively charged glass rod, what is the sign on the charge you acquire? Explain.
The charge will be positive because some of your electrons will flow onto the rod.
A flashlight bulb typically has a small metallic button at one end, and this button is surrounded by ceramic material. The chief purpose of the ceramic material is to insulate the button from the other contact point. What is the other contact point of the bulb?
The metal outside part where you see the threads to screw in the bulb.
An electron situated near another electron would feel
a repulsive electrical force.
Which type electromagnetic wave cannot travel through space?
all EM radiation can travel through space.
The position of maximum displacement would be the ____ of the wave.
antinode
The field lines always point __
away from positive charge
Two equal positive charges are near each other. If we increase the amount of charge on just one of them, then
both charges feel an increased electrical force.
The pitch of sound depends upon _____ of sound.
both frequency and wavelength.
The path that electric current follows is called the ___
circuit
A sound wave is a series of ____ and rarefactions.
compressions
An object that carries electricity well is said to be a __
conductor
F= kqq/r 2 is _______'s Law.
coulomb
The unit for the electric charge is the
coulomb
The top half of a transverse wave is the ___
crest
In a parallel circuit, if one bulb blows, the total current will _____
decrease
A positive charge is fixed at the origin. A positive charge is moved along the x-axis from x = 10 cm to x = 50 cm. The potential energy of the system
decreases
The electrical force between any two charged objects is
dependent on the sign of the charge on each object.
A uniform electric field has a magnitude of 10 N/C and is directed downward. A +0.5 charge is brought into the field. The charge will experience a force in the ______________ direction.
downward
The negative charge is carried by the _____.
electron
The particle flow in electricity is usually a flow of ______
electrons
A(n) __________ force is caused by an unbalanced charge.
electrostatic
In many ways, and electric circuit is like the plumbing system in your home. The switch in an electric circuit corresponds to the ________ in a plumbing system.
faucet or valve.
If the distance between two charged objects is halved, what is the change in electrostatic force?
four times larger
Which of the words below indicates the number of WAVES per SECOND?
frequency
Which type of electromagnetic radiation has the highest energy?
gamma
Two light bulbs are installed in two sockets, the sockets are connected in series, and power is then applied to the combination so that both bulbs light. If one of the bulbs is then removed from its socket, the other one will
go out
If you increase the potential difference or electromotive force across a resistance in a circuit the current flowing through that device will___.
increase
A positive test charge is moved closer to another positive charge. The potential of the test charge _______
increases
If the distance between two spherical charged objects decreases by a factor of two, then the electrical force between the objects
increases by factor of 4
Dead spots in an auditorium may be caused by__.
interference
Waves show both constructive and destructive____.
interference
When a battery is being used in a circuit some of the current is lost inside the battery due to ___
internal resistance.
According to Ohm's Law, the current is _____ to the resistance, if the voltage remains the same.
inversely proportional
The static electricity force is _____ the square of the distance between two charged objects.
inversely proportional to
An atom has
just as many electrons as protons.
The device in a circuit using the voltage is called the __
load
A ____ wave has particle motion that is parallel to the wave motion.
longitudinal
What are the units for the luminous flux of light?
lumens
A glass rod is rubbed with nylon. The rod is then brought close to the metal knob of an electroscope. A person's finger briefly touches the knob on the far side and is then removed. After the rod is removed the charge on the electroscope will be ______
negative
A rubber rod is rubber against hair. The rod is then touched to the metal knob of an electroscope. The sign of the charge on the electroscope after contact is ___________
negative
If we double frequency of a note, the sound changes by a(n) ___.
octave
If the distance between two charged objects is tripled, what is the change in electrostatic force?
one ninth as large
The excess charge on an object usually resides on the ____ of the object.
outside
Which of the words below indicates the number of SECONDS per wave?
period
The electric field created by a negative charge
points toward the charge.
A charged balloon can stick to a neutral wall because the wall is___
polarized
A glass rod is rubbed with silk so that the silk becomes negative. The rod is then used to charge an electroscope. The charge on the electroscope will be
positive if charged by contact.
The motion of an ocean wave toward the shore is the ___ of the wave.
propagation
A strip of fur is rubbed against a hard rubber rod. The rod thereby acquires a negative charge because
rubbing caused electrons to move from the fur to the rod.
A circuit with only one loop of wire or one path is called a ___ circuit.
series
The current (measured in Amperes) in a circuit is
the amount of charge (measured in Coulombs) that passes a point (in the circuit) in 1 second.
When you rub a rubber balloon on your hair
the hair gives electrons to the rubber balloon, giving the balloon a negative charge.
The amplitude of a transverse wave is measured from_____.
the middle (equilibrium) of the wave to the top or bottom of the wave
The resistance of a circuit element is a measure of
the ratio of the voltage difference between element ends to the current in the element.
After a glass rod is rubbed with a nylon cloth
the rod will have a positive charge and the cloth negative.
Compared to the magnitude of the charge on a proton, the magnitude of the electrical charge carried by an electron is
the same
A 12 ohm resistor and a 24 ohm resistor are connected in parallel across a 6.0 V battery. The correct statement from the following is
the voltage difference between the ends of each resistor is the same.
An unmarked resistor is being used in a circuit. To determine its resistance by making voltage and current measurements, one should connect
the voltmeter in parallel with the resistor, and the ammeter in series with the resistor.
In a series circuit, if one bulb of three bulbs in the circut goes out____.
they all go out
A ____ wave has displacement at right angles to the propagation.
transverse
If you double the number of negative charges on a balloon, what happens to the force of attraction of the balloon to a positive rod?
twice as large
The longest possible full wave for a wire will be ___ as the wire.
twice as long
A positively charged rod is brought close to an uncharged electroscope. While the rod is close, one's finger touches the far side of the metal ball on the electroscope. The rod is removed and then the finger is taken away. The electroscope is
uncharged
It is observed that a positive charge released between the parallel plates of a capacitor moves upward. The direction of the electric field between the capacitor plates is_________
upward
The unit for electromotive force (emf) is
volt
In a parallel circuit, the ___ is the same in all the resistors, even if the individual resistors vary.
voltage drop
