Physics lab 3
A solid circular disk conductor with a cavity at the center carries a total charge of +7 Coulombs. Within the cavity, insulated from the conductor, is a point charge of -2 Coulombs. How much charge is on the inner surface of the conductor -7 C -2 C -5 C +2 C +5 C
+2 C
A solid circular disk conductor with a cavity at the center carries a total charge of +7 Coulombs. Within the cavity, insulated from the conductor, is a point charge of -2 Coulombs. How much charge is on the outer surface of the conductor e) -7 C a) -2 C b) -5 C c) +2 C d) +5 C
+5 C
Let's place a test charge Q = 7.0x10^-6 C into the region of space occupied by a constant electric field of 3.129x10^4 N/C. The field will act on a test charge with a force of a magnitude a) 4.47x10^9 N b) 22.4x10^6 J c) 0.219 J d) 2.19x10^-1 N e) 0.22 N
.22 N
How much work is required to move a charge of 0.05 C through a potential difference of 6 V? 0.11 J 0.3 J 11 J 3 J
.3 J
Electric field of a magnitude E=40.0 N/C is detected at r=5.0 m from it's source, which is a point charge Q which has a charge of...(Hint: use k=9.0E9 N*m^2/(C^2)) a) 2.41x10^-7 C b) 1.11x10^-7 mC c) 0.000000111 C d) 1.1x10^-7 C e) 2.22x10^-8 C
1.1x10^-7 C
A 2 Coulomb charge experiences a force of 20 N. The electric field strength is 10 N/C 20 N/C 30 N/C 40 N/C
10 N/C
Charge of uniform surface density 0.20 nC/m^2 is distributed over the entire xy plane. Determine the magnitude of the electric field at any point having z=2.0m? a) 17 N/C b) 11 N/C c) 23 N/C d) 28 N/C e) 40 N/C
11 N/C
If 9.1x10^2 joules of work is done in moving 45.5 C of electric charge from one terminal of a battery to the other, how many volts is the battery providing? 2x10^0 2x10^2 0.050 20. 0.05
20
A uniform electric field of 2x10^5 N/C exists between two conductor plates separated by a distance of 15 cm. What is the voltage difference between them? 30000V 3000V 13333.33 133.33
30,000V
How much work is done in moving 5.0 C of electric charge from one terminal of a 9.0 V battery to the other? a) 1.8 J b) 0.56 J c) 45 J d) 60 J e) 25 kJ
45 J
Two infinite parallel surfaces carry uniform charge densities of 0.20 nC/m^2 and -0.60 nC/m^2. What is the magnitude of the electric field at a point between the two surfaces? 34 N/C 23 N/C 45 N/C 17 N/C 90 N/C
45 N/C
Electric field of a magnitude E=40.0 N/C is detected at r=5.00 m from it's source, which is a point charge Q=1.11x10^-7 C. What is the magnitude of an electric force that acts on an electron separated by R=5.0 m from Q ? (Hint: electron's charge equals 1.602x10^-19 C) 6.41 N/C 6.408 N/C 40.0 N 6.408x10^-18 N 6.41x10^-18 N
6.41 x 10^-18 N
Electric field of a magnitude E is detected at R=10.00 m from its source, which is a point charge Q=1.11x10^-7 C. What is the magnitude of the electric field? (Hint: use k=8.99x10^9 N*m^2/C^2) a) 9.98 N b) 9.978989 N/C c) 10.0 N/C d) 9.98 N/C e) 10 N/C
9.98 N/C
Which one of the following quantities is a vector (quantity that has magnitude and direction)? a) Electric charge b) Energy c) Electric field d) Potential difference
Electric field
The electric field produced by an infinite plane sheet of charge at a point P that is r distance away from the sheet is ____________from the sheet. Directly proportional to the distance r Directly proportional to the distance r^2 Inversely proportional to the distance r^2 Independent of the distance
Independent of the distance
The electric field at a point P that is r distance away from a very small ring of charge such that r is much greater than the diameter of the ring is Directly proportional to the distance r Directly proportional to the distance r^2 Inversely proportional to the distance r Inversely proportional to the distance r^2
Inversely proportional to the distance r^2
Electric field lines must be ___________to the surface of a conductor a) Perpendicular b) Parallel c) Random d) Field lines are not present at the surface of a conductor
Perpendicular
If the surface charge density of a uniformly charged disk is negative, the directions of the electric fields on both sides of the plane are ________ a) Away from the disk planes b) Toward the disk planes c) Random d) Electric fields on both sides of the disk cancels out
Toward the disk planes
The electric field between oppositely charged plates is __________ if the plate separation is much smaller than the dimensions of the plates. Uniform Nonuniform Zero Directly proportional to the square of plate distance Inversely proportional to the square of plate distance
Uniform
Equipotentials are lines along which A) The electric field is constant in magnitude and direction. b) The electric charge is constant in magnitude and direction. c) a charge moving at constant speed requires that the maximum amount of work be done against electrical forces. d) a charge may be moved at constant speed without work against electrical forces. e) charges move by themselves.
a charge may be moved at constant speed without work against electrical forces
During the experimental procedure if a signal change appears it means there is a) NO difference in electric potential between the two scope probes b) an intersection of electric lines of force c) an intersection of equipotential lines d) a measurable difference in electric potential between the two probes e) a short circuit in your experimental circuit set-up
a measurable difference in electric potential between the two probes
According to Coulomb's law the magnitude of the force of attraction or repulsion between two electric charges, both at rest, varies a) inversely as the product of the charges and directly as the square of the distance between the charges b) inversely as the product of the charges and inversely as the square of the distance between the charges c) directly as the product of the charges and directly as the square of the distance between the charges d) directly as the product of the charges and inversely as the square of the distance between the charges e) directly as the product of the charges and inversely as the square root of the distance between the charges
directly as the product of the charges and inversely as the square of the distance between the charges
In the field surrounding a positively charged particle the electric field lines of force a) are directed radially inward b) emanate radially outward c) surround the charged particle d) form equipotential contours about the charged particle e) are randomly dispersed about the charged particle
emanate radially outward
Which of the following is true? a) equipotential lines are perpendicular to respective lines of force b) equipotential lines are parallel to respective lines of force c) families of equipotential lines originate on positive charges d) work is done only when a charge is moved along an equipotential line or surface e) when a charge is moved from one equipotential surface to another equipotential surface the net work done is zero joules
equipotential lines are perpendicular to respective lines of force
The potential decreases as one moves _________of the electric field. a) in the same direction as b)in the opposite direction as c)None of the above
in the same direction as
The electric field at a point P that is r distance away from an infinitely long line of charge is Directly proportional to the distance r Directly proportional to the distance r^2 Inversely proportional to the distance r Inversely proportional to the distance r^2
inversely proportional to the distance r
If the distance between two charges is halved, the electrical force between the charges Is two times stronger Is two times weaker Is four times stronger Is four times weaker
is four times stronger
The work required to move a unit positive electrical charge from one point in space to another equals potential difference (or voltage) between these two points. SI unit for potential difference(voltage) is called a volt and can be expressed as a) coulomb/joule b) newton/coulomb c) watt*second d) joule*coulomb e) joule/coulomb
joule/coulomb
Qualitatively speaking... like electric charges attract one another opposite charges repel one another opposite electric charges annihilate one another charges never occur singly--they occur only as dipoles like electric charges repel one another
like charges repel one another
The nature of an electric field can be studied quantitatively by measuring the a) magnitude and direction of the force exerted on a positive test charge b) magnitude and direction of the force exerted on a magnetic compass c) magnitude and direction of the force exerted on a test mass d) magnitude and direction of the force exerted on a neutron e) magnitude and direction of the force exerted on a north magnetic pole
magnitude and direction of the force exerted on a positive test charge
Since a test charge at rest with respect to a static electric field experiences a well-determined force, one can observe that electric field lines of force a)never intersect one another b) are everywhere parallel to the equipotential surface c) are everywhere parallel to each other d)sometimes intersect one another e)always intersect one another
never intersect one another
A test charge (used in order to detect an electric field) must a) produce a significant magnetic field b) alter the electric field of interest c) not alter the electric field of interest d) be an electron e) move in the direction which is perpendicular to the force line
not alter the electric field of interest
Between two point charges, lines of force of an electric field created by these charges can be mapped. By convention the lines of force a) originate on negative charges and terminate on positive charges b) originate on positive charges and terminate on negative charges c) cross one another at points of equal potential d) are respectively parallel to the corresponding map of equipotential lines e) form closed loops inside the respective charges
originate on positive charges and terminate on negative charges
Electric field lines must be ___________to any equipotential surface Perpendicular Parallel Tangent None of the above
perpendicular
Since work is done only when the net exerted force has some component along the direction of displacement, it necessarily follows that electric lines of force are a)perpendicular to the equipotential surface everywhere b)parallel to the equipotential surface everywhere c)NOT the cause of potential differences d)NOT the cause of energy stored or released when charged particles are moved from one equipotential surface to another e) always considered as working forces
perpendicular to the equipotential surface everywhere
To measure the intensity of an electric field a(n) _____ is used. electron proton positive test charge negative test charge neutron
positive test charge
Which of the following statements is TRUE? a) the electric field internal to an aluminum ring is randomized b)the electric field internal to an aluminum ring is zero c) the electric field intensity inside an aluminum ring is greater than the intensity outside the ring d) the lines of force inside the ring were a continuation of the lines of force outside the ring e) the equipotential lines measured inside the ring represented the same voltages as outside the ring
the electric ring internal to an aluminum ring is zero
When a charged particle is moved along an electric field line, a) the electric field does no work on the charge. b) the electrical potential energy of the charge does not change. c) the electrical potential energy of the charge undergoes the maximum change in magnitude. d) the voltage changes, but there I sno charge in electrical potential energy. e) the electrical potential energy undergoes the maximum change, but there is no change in voltage.
the electrical potential energy undergoes the maximum change, but there is no change in voltage
To detect the existence of a force field, an appropriate test particle of some kind is used. For example a _____ is used to detect the existence of a gravitational force field while a _____ is used to detect the existence of an electric field. {test charge..compass} {test magnet..test charge} {compass..test mass} {test mass..test charge} {test mass..test magnet}
{test mass, test charge}
