Physics 2 Final Exam Review
Consider an AC circuit containing a coil, capacitor, and resistance. Tripling the frequency will change the circuits impedance by what factor?
info insufficient to determine answer
The magnet moving past an object will produce eddy currents in the object if the object:
is a conductor
When a light bulb is turned on, its resistance increases until it reaches operating temperature. What happens to the current in the bulb as it is warming up?
it decreases
A resistor is made of a material that has a resistivity that is proportional to the current going through it. If the voltage is doubled, what happens to the current going through it?
it increases by a factor of 2^(1/2)
The induced current appears almost instantaneously for loops close together. How can this energy exchange happen?
it is done via an electromagnetic wave
As the current is going from 10A in one direction to 10A in the other, in which direction is the induced current in this side of the square coil nearest to the straight line?
it is in the positive y-direction
If the current in a wire is tripled, what effect does this have on the electron drift velocity in the wire?
it triples
A magnet is dropped so it falls lengthwise toward the center of the ring. Will the magnet be attracted to the ring or repelled by the ring?
it will be repelled
If two parallel, conducting plates have equal positive charge, the electric field line will:
leave both plates and go to inifinty
The wave=particle duality of light means that, in the same experiment:
light will act either like a wave or like a particle
The magnetic pole of the Earth nearest the geographic North Pole corresponds to which of the following?
magnetic south pole
At which location will the electric field between the two parallel plates of a charged capacitor be the strongest in magnitude?
midway between the two plates nearest the senter
In an LCR series circuit, xL>xC. The phase angle is 30 degrees. If the Ac frequency doubles, what is the magnitude of the resulting phase angle?
more than 30 degrees
Each of three naturally occurring radioactive series start with one of the following isotopes except?
237NP
If it takes time T for the average conduction electron to traverse the 1mm wire, how long does it take for such an electron to traverse the 2mm wire?
8T
If the size of the charge value is tripled for both of two point charges maintained at a constant separation, the mutual force between them will be changed by what factor?
9
In an RLC series circuit, if the AC frequency is increased to a very large value, what value does the phase angle between the current and voltage approach?
90
When voltage is generated by rotating a coil in a magnetic field, the period of the voltage equals the time that it takes for the coil to rotate through ______ radians.
2pi
A length L of wire has a voltage V across its ends while current I runs through the wire. If a voltage 3V were applied to another length of this same wire, what is the length of this second wire?
3L
In a Young's double-slit interference apparatus, the distance from the slits to the screen is quadrupled. The distance between adjacent light and dark fringes changes by a factor of:
4
What is the critical angle for total internal refraction for a ray of light going from material 1 to 2?
45 degrees
By what factor is the self-inductance of an air solenoid changed if its length and number of coil turns are both multiplied by 7?
7
By what factor is the self-inductance of an air solenoid changed if only its cross-sectional are, A, is multiplied by 8?
8
What is the resulting equation from applying Kirchhoff's junction rule to point B?
I1+I2+I3=0
The units T*m^2/s are equivalent to:
V
A certain capacitor is charged to 10V and then at t=0, allowed to discharge through a resistor. There will be a certain time before the voltage reaches 5V. The time can be decreased by increasing?
none of the above
In an RLC circuit, the max current is 1 amp. What is the average current?
none of the above
A current in a solenoid with N turns creates a magnetic field inside the solenoid. The magnetic field strength is directly proportional to the
number of turns in the loop; current strength
If the loop area increases, what effect does this have on the induced current?
the induced current is counterclockwise
Electricity may be generated by rotating a loop of wire between the poles of a magnet. The induced current is greatest when
the plane of the loop is parallel to the magnetic field
The electric field associated with a uniformly charged hollow metallic sphere is the greatest at?
the sphere's outer surface
A light bulb is connected to a 12-V battery. Because light bulbs are non-Ohmic, the resistance of the bulb is not constant, but increases as the bulb gets hotter. As the bulb heats up, which value remains unchanged?
the voltage across the bulb
Two wires are arranged so that wire A points North and wire B points east, the wires crossing at their midpoints. Which is true?
there are no forces, but the net force on each wire is zero
A stationary Q is located in the magnetic field. The direction of the magnetic force on Q is?
there is no magnetic force
The size of the electric current in an electrical conductor is a function of which of the following?
velocity of charge carriers; conductor cross-sectional area; density of charge carriers
A proton and a deuteron are moving with equal velocities perpendicular to a uniform magnetic field. A deuteron has the same charge as the proton but has twice its mass. The ratio of the magnetic force on the proton to that on the deuteron is:
2
Super conductivity was discovered by:
Onnes
The electric field E, in an electromagnetic wave, is oriented in what direction with respect to its associated magnetic field, B?
E perpendicular to B
The rate of heat dissipation in an AC circuit with resistance, R, the effective current, Irms, is given by which of the following?
(Irms)^2R
Two equal charges, each Q, are separated by some distance. What third charge would need to be placed half way between the two charges so that the net force on each charge would be zero?
-Q/4
By what factor does the max energy stored in a series RL circuit change if the resistance is doubled and the inductance is tripled?
0.75
The lowest possible value for the index of refraction is:
1
In circuits involving resistors and capacitors, the quantity 63% often arises. Which is equivalent to this quantity?
1-e^-1
A resistor is connected to a battery with negligible inertial resistance. If you replace the resistor with one that has triple the resistance, by what factor is the power dissipated in the circuit change?
1/3
If the distance between two point charges is increased by a factor of three, the resultant potential energy is what factor times the initial potential energy?
1/3
If you replace the resistor with one that has quadruple the resistance, by what factor does the power change?
1/4
Replacing a resistor with one that has two times the diameter will change the resistance by what factor?
1/4
Replacing a wire resistor with another of the same material but with three times the diameter will have the effect of changing the resistance by what factor?
1/9
Three capacitors have capacitances c1<c2<c3. If these capacitors are connected in a series, which of the following is true for the resulting equivalent capacitance?
Ceq<c1
If the induced current in a wire loop were such that the flux it produces were in the same direction as the change in external flux causing the current, which of the following conservation laws would end up being violated?
Energy
Which statement regarding the force of a magnetic field on a current-carrying wire is true?
all of the above are false
The quantity volt is equivalent to:
J/C
Which is a unit of power?
J/s
Electric field is dimensionally equivalent to which of the following?
N/C
The constant Ke is equivalent dimensionally to which of the following?
Nm^2/c^2
A conducting spherical shell of inner radius r1 and outer radius r2 has a charge Q on it. An additional charge, also Q, is then added to the sphere. What is the resulting charge per unit area on the outer surface of the sphere?
Q/2pi(r2)^2
If R1 < R2 < R3, and if these resistors are connected in parallel in a circuit, which one has the highest current?
R1
Three resistors R1, R2, and R3 are connected in parallel. Which expressed the total resistance of the three resistors connected in parallel?
RT=((1/R1)+(1/R2)+(1/R3))^-1
Three resistors are connected in series. Which expressed the total resistance of the three resistors?
RT=R1+R2+R3
Three resistors, each of different value, are used in a circuit with a power source applying 12V. For which of the following resistor combinations is the total power supply greatest?
all three resistors in parallel
When charge Q1 is placed at point P1, the resulting potential at point P is V1. When Q2 is placed at point P2 after Q1 is in position at P1, the resulting potential at P becomes V2. What is the potential at point P if charge Q1 is then removed?
V2-V1
The unit for rate of energy transformation, the watt, in an electric circuit is equivalent to which of the following?
VA
Which of the following expresses the total resistance across three resistors connected in parallel?
VT=V1=V2=V3
An RLC circuit is connected across an AC power source. How are the max and rms voltages from the power source related?
Vmax=(sqrt2)Vrms
Electrical charges and magnetic poles have many similarities but one difference is...
a magnetic pole cannot be isolated
Which condition of motion must be met with regard to a charge particle if it is in the process of emitting electromagnetic radiation?
accelerates
In Huygen's construction, all points on a wave front:
act as point sources for the production of secondary spherical waves
Which of the following characteristics are held in common by both gravitational and electrostatic forces when dealing with either point masses or charges?
all of the above
A free electron is in an electric field. With respect to the field, it experiences a force acting:
anti-parallel
An RLC circuit is connected across an Ac power source. Which statement is correct?
at resonance, the phase angle between the current and voltage is 0
An inductor, battery, resistance, and ammeter and switch are connected in series. If the switch, initially open, is now closed, what is the current's final value?
battery voltage divided by resistance
Transmitting power at high voltage (400,000 V), reduces the power loss for transmission lines. How then can 400,000 V be used in a normal house?
before reaching households, transformers are used to reduce the voltage appropriately
Which of the following best characterized electrical insulators?
charges on the surface don't move
Which of the following combinations of circuit components can be used to make a tuner for a radio to select the desired frequency?
fixed inductor, variable capacitor
How is the energy stored in a current-carrying inductor related to the current value, I?
directly proportional to I^2
How is the energy stored in a current-carrying inductor related to its self-inductance, L?
directly proportional to L
The rms current is equal to the direct current that
dissipates an equal amount of energy in a resistor at the same rate as in an AC circuit
If a proton is released at the equator and falls toward Earth under the influence of gravity, the magnetic force on the proton will be toward the ____ assuming the magnetic field is directed toward the north at this location.
east
A straight wire of length ℓ is oriented east-west and is in a magnetic field B pointing north. Which end of the rod is positively charged?
east end
An electromagnetic wave is made up of which of the following oscillating quantities?
electric and magnetic fields
The function of the electric motor is which one of the following conversion processes?
electrical energy to mechanical
When an RLC series circuit is in resonance, its impedance is:
equal to its resistance
The ideal transformer is one that:
experience no power loss
The current in a long wire creates a magnetic field in the region around the wire. How is the strength of the field at distance r from the wire center related to the magnitude of the field?
field inversely proportional to r
The electric field at the surface of a positively charges conductor has a direction characterized by which of the following?
perpendicular outward and away from the charge
How is the direction of propagation of an electromagnetic wave oriented relative to the associated E and B fields?
perpendicular to both E and B
One phenomenon that demonstrates the particle nature of light is:
photoelectric effect
A ray of light passes from one material into a material with a higher index of refraction. Which quantity remains unchanged?
photon energy
The loop passes over the magnet's center at position B and moves away from the magnet at C. For which position is the induced current zero?
position B
If the distance between two isolated points that are oppositely charged is changed, the electric field between the plates is essentially unchanged. However, the...
potential difference between the plates will double
An uncharged spherical shell has a charge q carefully placed at its center through a small hole. The charge q does not touch the shell. What is the charge on the outer surface?
q
When light from air hits a smooth piece of glass with the ray perpendicular to the glass surface, which of the following will occur?
reflection and transmission with theta2=0 degrees
Equipotential surfaces around a point charge are:
spherical
A triangular current has twice as many turns as the square coil. Which coil experience the greater torque when a 30 degree angle is made?
square coil
The current is greatest at which of the following times as measured after the switch is closed?
ten time constants
3 loops of wire, 1 circular, 1 rectangular, and 1 square are made from identical lengths of wire. If the loops are in the same increasing magnetic field perpendicular to the plane of the coils, which loops has the greatest induced emf?
the circular one
If a conductor is in electrostatic equilibrium near an electric charge
the electric field inside the conductor must be zero
The operation of an electric motor depends on which of the following effects?
the force acting on a current-carrying wire in a magnetic field
As long as the current in the primary is steady at 3.0A, the current in the secondary will be:
zero
In an AC circuit, the current in a pure resistor differs in phase with the applied voltage by what angle?
zero
