Physics 2 final (test 1 material)
when current is flowing in an ordinary metal wire, the magnitude of the average velocity of the electron is closest to
1 mm/s
When a dielectric material is introduced between the plates of a parallel-plate capacitor and completely fills the space, the capacitance increases by a factor of 4. What is the dielectric constant of the material that was introduced?
4
An ideal parallel-plate capacitor has a capacitance of C . If the area of the plates is doubled and the distance between the plates is halved, what is the new capacitance?
4C
as a proton moves in the direction of electric field lines
It is moving from high potential to low potential and losing electric potential energy
A dielectric material such as paper is inserted between the plates of a capacitor as the capacitor holds a fixed charge on its plates. what happens to the electric field between the plates as the dielectric is inserted?
The field becomes weaker.
Consider two copper wires of equal cross- sectional area. one wire has 3 times the length of the other. How do the resistances of these to wires compare?
The longer wire has 3 times the resistance of the shorter wire
A
Which one of the arrows shown in the figure best represents the direction of the electric field between the two uniformly charged metal plates?
X and Y are two initially uncharged metal spheres on insulating stands, and they are in contact with each other. A positively charged R is brought close to X as shown in part (a) of the figure. sphere Y is now moved away from X, as shown in part (b). What are the final charge states of X and Y?
X is negative and Y is positive.
As a proton moves in a direction perpendicular to the electric field lines
both its electric potential and electric potential energy remain constant.
as more resistors are added in series to a constant voltage source. the power supplied by the source
decreases.
A hydrogen atom consists of a proton and an electron. If the orbital radius of the electron increases, the electric potential energy of the electron due to the proton
increases
the length of a certain wire is kept same while its radius is doubled. hat is the new resistance of this wire?
it is reduced by a factor of 4.
when a current flows through a metal wire, the moving charges are
only electrons
Doubling the potential across a given capacitor causes the energy stored in the capacitor to
quadruple
if the current flowing through a circuit of constant resistance is doubled, the power dissipated by that circuit will
quadruple in magnitude.
four unequal resistors are connected in a parallel with each other. what statement is correct about this combination?
the equivalent resistance is less than that of the smallest resistor.
B
three equal charges +Q are at three of the corners of a side d. a fourth charge +Q of equal magnitude is at the center of the square as shown in the figure. which one of the arrows shown represents the net force acting on the charge at the center of the square?
B, A, C.
Identical light bulbs can be attached to identical ideal batteries in three different ways (A, B, or C) as shown in the figure. The ranking (from lowest to highest) of the total power produced by battery is
Two point charges, Q1 and Q2, are separated by a distance R. If the magnitudes of both charges are doubled and their separation is also doubled, what happens to the electrical force that each charge exerts on the other one?
It remains the same.
how much kinetic energy does a proton gain if it is accelerated, with no friction, through a potential difference of 1.00V?
1.00 eV
Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude F due to the other. With time, charge gradually diminishes on both spheres by leaking off. when each of the spheres has lost half its initial charge, what will be the magnitude of the electrostatic force on each one?
1/4 F
Only (i) is true
The figure shows electric field lines arising from two small charged particles P and Q. consider the following two statements: (i) the charge on P is smaller than the charge on Q (ii) the electrostatic force on P is smaller than the force on Q. which of the above statements is true?
two tiny beads are 25 cm apart with no other charges or fields present. Bead A caries 10 micro coulombs of charge and bead B caries 1 micro coulomb. what statement is true about the magnitudes of the electric forces on these beads?
The force on A is exactly equal to the force on B
The potential at points A and B are equal, and the potential at point C is lower than than the potential at point A
A region of space contains a uniform electric field, directed toward the right, a shown in the figure. Which statement about this situation is correct?
Trajectory Z
An electron is initially moving to the right when it enters a uniform electric field directed upwards, as shown in the figure. which trajectory (X,Y,Z, or W) will the electron follow in the field?
B
Three equal- magnitude point charges of varying signs are placed at three of the corners of a square of side d as shown in the figure. which one of the arrows shown represents the direction of the net electric field at the vacant corner of the square?
the electron-volt is a unit of
energy
resistance
for the graph shown in the figure, what physical quantity does the slope of the graph represent for ohmic material?
Kirchhoff's junction rule is a statement of
the law of conservation of charge
q1 is negative and q2 is positive; the magnitude of q1 is less than the magnitude of q2.
two stationary point charges q1 and q2 are shown in the figure along with a sketch of some field lines representing the electric field produced by them. What can you deduce from the sketch?
