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Rio Salado PHY comprehensive
Real questions and Answers exam
2026 GRADE A+
which of the following statements regarding static electric
charge is most accurate - - correct answers
only----force is proportional to the inverse square
distance between the charged particles An object has a positive net charge. The most likely reason
for the net charge is that - - correct answers
only----electrons were transferred off the object
what is the net charge on an object that has gained
8x10^13 electrons - - correct answers
only----8x10 ^13 * 1.6 x10^- 19
=-1.3 x10^- 5 which of the following processes will not result in a
change in net charge on an object? - - correct
answers only----polarization
which of the following is an example of an insulation - -
correct answers only----a piece of paper
a block of wax a block of glass
all of the above are examples which of the following statements concerning charge is
most accurate - - correct answers only---
- the total charge present in the system and surroundings
is constant in any process Two charged particles both have positive net charges. They are near each other and released from rest. Which of the following statements best describes the interaction of
the particles? - - correct answers only---
- The particles will repel. As they get further apart, the
repelling force will decrease Particle A has a net charge of - 5uC. Particle B has a net charge +10uC. Which of the following is the largest force?
- - correct answers only----they apply
the same force on each other Which of the following statements concerning the
structure of an atom is accurate? - - correct
answers only----neutrally charged atoms
contain equal amounts of protons and electrons Two identical metal blocks are in contact side-by-side. A positively charged rod moves near the left block. Which of the following most accurately shows the resulting
distribution of charge throughout the metal blocks? - -
correct answers only----When a
positively charged rod moves near the left of the block, it attracts or pulls negative charge of the block.
correctly explains this behavior - - correct
answers only----both spheres have a negative
net charge both spheres have a positive net charge both a and b are possible Three charged particles are held in place. Particle A has a net charge of +2 uC and is at (0,0)m. Particle B has a net charge of - 4uC and is placed a (.5,0) m. Particle C has a net charge of - 4uC and is at(0,0.5) m. What is the magnitude of
the net force on particle A - - correct answers
only----9x10^9 (2x10^-6)(4x10^-6)/.5^
sqrt(.16588) =0. Three charged particles are held in place. particle A has a net charge of +2 uC and is at (0,0)m. Particle B has a net charge of +4 uC and is placed a (0.5,0)m. Particle C has a net charge of - 4uC and is placed at (0,0.5)m. What is the
angle of direction of the net force acting on particle A - -
correct answers only----135 degrees
Which of the following statements regarding charge is
most accurate? - - correct answers only--
--charge is a fundamental property of matter
proteins and electrons carry equal amounts of charge two types of charge are possible all of the above are accurate
A particle with a net charge of - 2uC is halfway between two particles with a net charge of +4 uC and +6uC respectively. The two positively charged particles are 10 cm apart. What
is the magnitude of the net force on the negative particle -
- correct answers only----F=kqq/r^
9x10^9 (4x10^-6)(4x10^-6)/.1^
charged particles A and B experience a statice electric force of F. If the distance between the charge particles
triples, then the static electric force becomes - -
correct answers only----1/9F
An electroscope is a device that has small gold foil strips suspended from a metal rod. A student brings a negatively charged rod near the top of a neutral electroscope. The student then briefly touches a hand to the top of the electroscope before removing the charged rod. The foil strips of the electroscope now spread apart. The student then brings a different rod near the top of the electroscope. The leaves of the electroscope move closer together (see
below). The new rod must have a net charge that is - -
correct answers only----negative
which of the following statements concerning charge is
most accurate - - correct answers only---
- The total charge present in the system and surroundings
is constant in any process Twp neutral blocks are in physical contact side-by side. Block A is on the left, and block B is on the right. A
100m/s Two charged parallel plates have a uniform field strength of 1200N/C between them. If the separation distance between the plates is 0.15m what is the potential difference
between the plates> - - correct answers
only----V=ER
V=1200 (0.15)
=180 V
an electron moves from a position next to a negatively charged source to a position next to a positively charged
source. Which statement is accurate? - - correct
answers only----The electron will lose energy
and move to a higher potential A particle with a charge of +2uC is at the position marked by x. Which statement concerning the particle's energy is
most accurate? - - correct answers only--
--The particle will have a positive energy term
How much energy does it take to move a particle with a charge of +2nC, from an initial position infinitely far from a second particle with a charge of +3mC to a final position
0.2 from the second particle - - correct
answers only----(9x10^9) (2x10^-9)(3x10^-3)/.
0.27 J
Consider a uniform electric field of 50N/C directed towards the east. If the potential measured at some point in the field is 80V, what is the potential at a position 1.0 directly
east of that point - - correct answers only-
---V=Er
80=50 R
R=1.
50 x .6= 30V
The following diagram is best described as - -
correct answers only----the electric field
near two positive charges
Equipotentials are best defined as - - correct
answers only----positions in an electric field
where multiple positions have the same voltage
Which statement regarding voltage is most accurate? - -
correct answers only----Positive voltages
occur near positive sources and negative voltages occur near negative point sources
Electric potential is - - correct answers
only----the ratio of energy per amount of charge on a
particle is an electric field
The electronvolt is a unit that measures - - correct
answers only----energy
correct answers only----The arrows
represent the direction of the electric field, the circles represent positions with equal potential, and the source charge is negative Which of the following correctly shows the equipotentials
near a negative point source - - correct
answers only----C
When drawling the equipotential 3D maps, positive point
sources will form - - correct answers
only----hills
charged particles are at the corners of equilateral triangles, which all have the same area. Rank the magnitude of the electric field strength at point P in each triangle from
greatest to least - - correct answers only-
---A=B=D>C
A negatively charged particle moves through various electric fields. Which of the following correctly indicates whether the negatively charged particle gained or lost
energy in each of the following examples - - correct
answers only----gained energy
lost energy gained energy An electron moving to the right at a constant speed moves into an electric field. The electric field is to the left. Which of the following correctly indicates how the field will affect
the electron's motion - - correct answers
only----the electrons will speed up q
an electron moves through a potential difference of 1500V. The magnitude of the charge in potenial energy
experienced by the electron is - - correct
answers only----1500eV
which statement regarding electric potential is not
accurate - - correct answers only----
electric potential depends on the amount of charge on a particle in an electric field which of the following statements regarding equipotentials
and electric fields is accurate - - correct
answers only----Electric field lines are
perpendicular to equipotentials and electric fields is accurate The units used to measure the strength of an electric field
are - - correct answers only----Newtons
per Coulomb which of the following explains why international travelers need to use special adapters when plugging a device designed to operate in the US into a wall outlet in Europe
(Vrms in the US is 120V while Vrms in Europe is 240V) - -
correct answers only----the increased
voltage causes an increase in power usage and the device will overheat
How much energy will an electron gain if it moves through
a potential difference of 1V - - correct answers
only----1 eV
the US has an alternating current frequency of 60Hz. China has an alternating current frequency of 50 Hz. this means
that - - correct answers only----the
number of times voltage cycles in a minute in the US is greater than the number of times voltage cycles in china A battery with a potential difference of V connects to a resistor, and the resulting current is measured. You remove the battery, and a new battery with a potential
difference of 2Vis put in its place. As a result - -
correct answers only----the current will
double a 9.0 Vbattery connects to a wire resistor. The wire resistor is tungsten (resistor 5.6x10^-8) 0.5m long has a radius of
1.2x10^-5m. What is the current through the resistor - -
correct answers only----0.15 A
a battery connects to a resistor. The rate of energy dissipated by the resistor is 1.44 W The rate of energy
supplied by the battery is - - correct answers
only----equal to 1.44 W
A particular alternating voltage supply completes one full
voltage cycle at a frequency - - correct
answers only----equal to 10Hz
Which of the following statements concerning
conventional current is correct? - - correct
answers only----Conventional current is the
movement of positive charge and flows through a circuit in a direction from positive to negative wire resistor A has twice the length and twice the cross sectional area of wire resistor B. Which of the following accurately compares the resistances of wire resistors A
and B - - correct answers only----wire A
has the same resistance as wire B use the following voltage verses current data to determine
the resistance of a particular resistor - - correct
answers only----(24-0)/1.5- 0
A device plugged into a wall outlet experiences an alternating current. The RMS current value is 2A. The peak
current is - - correct answers only----2x
sqrt =2. A battery connects to a resistor with resistance R and the resulting current is measured. The resistor is removed and a new resistor with a resistance of 2R is added. As a result
A battery with an emf of 12V connects in parallel to a 50 ohm and 25 ohm resistor. The current through the battery
is 0.70 A. What is the internal resistance of the battery - -
correct answers only----50 x25 / 50+
E=I(Req +r) 12=0.7(16.6 +r) 12=11.66 +0.7r 0.333=0.7r 0.54 ohm What is the magnitude of the magnetic field strength at a
position 1.0cm away from a wire with 3.0A of the current -
- correct answers only----B=uoI/2pir
4pi x10^-7(3)/(2pi)(0.01) 6x 10^- 5 The maximum torque on a set of 20 square loops with edge
lengths of 6cm in a 4.0T magnetic field is - - correct
answers only----T=NIABsintheta
Not enough information is stated. The torque depends on the amount of current in the loop If each of the resistors has identical resistance of R, what
is the total circuit resistance? - - correct
answers only----R+ Rx2R/(R+2R)
5/3 R
Magnetic effects are caused by - - correct
answers only----moving charge
Two parallel wires are oriented vertically (i.e. along the vertical edge of the screen). The wire on the left has the current of 2.0A directed upward. The wire on the right has a current of 4.0A also directed upwards. Which statement
is most accurate - - correct answers only-
---The wire will experience an attracting force
What is the direction of the magnetic force on the wire? (the current in the wire is flowing to the right.) <--------- <--------- pipe I ------> <---------
<---------- - - correct answers only----No
force A wire carries 8A of current directed to the left. What is the magnitude of the initial force on a +6mC charged particle that is moving at a speed of 2000m/s to the left at a
distance 6.0mm from the wire? - - correct
answers only----B=uoI/2pir
F=q(vxB) F=uoIqv/2pir 4pi x 10^-7 (8) (0.006)(2000)/2pi 0. What is the direction of the magnetic field at the position marked by the X
Which of the following correctly identifies the initial direction of the force on the moving positively charged particle(i.e current in the wire is directed to the left as indicated by the arrow) <----------- pipe
positive particle-------> - - correct answers
only----down
What is the magnitude fo the force on a +3mC charge moving at a speed of 1000m/s through a 1.25T magnetic
field - - correct answers only----Fm=BvQ
1.25 x 1000 x 3x10^- 3 3.75 N Two parallel wires are horizontally oriented. The top wire has a current of some value I directed to the left, and the bottom wire has current of 2xI directed to the right. At what
point will the magnetic fields cancel out? - - correct
answers only----some point above the wire
A positively charged 2mC particle moving in the upward direction at a speed of 20m/s enters a 3.0T field directed into the page. The particle path curves with a radius of
6cm. What is the mass of the particle - - correct
answers only----qvB= mv^2/r
m=qbr/v m= (2x10^-3) (3T) 0.06)/ 1.8 x10^- 5
Which of the following correctly identifies the initial direction of the force on the moving positively charged particle O O O O O O O O O O O O O O O O ^ I I
+ particle - - correct answers only----
right What is the direction of the magnetic force on the wire
current directed into the screen - - correct
answers only----right
what is the magnitude of the force on a 0.5m wire that has 4.0 A of current in a uniform magnetic field of 2.0T? The wire and the magnitic field are perpendicular to each other
- - correct answers only----F=BIL
2x4x0. F=4N Which of the following correctly identifies the initial direction of the force on the moving negatively charged particle <-------- <-------- <------ negative particle <-------
<------- - - correct answers only----no
force
