AP Physics 2 : AP Physics 2
Study concepts, example questions & explanations for AP Physics 2
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Example Questions
Example Question #3 : Magnetism And Electromagnetism
A conductive rod is moving through a region of magnetic field, as diagrammed above. As a result of its motion, mobile charge carriers in the conductor separate, creating an electric potential across the rod. When, if ever, do the charge carriers cease this motion?
The motion stops when the electric field strength created by the separated charge equals the magnetic field strength.
The motion stops when the electric potential equals the magnetic field strength.
The motion stops when the magnetic field created by the separated charges equals the external magnetic field.
The motion does not stop. Mobile charge carriers continue to separate as long as the rod remains in motion.
The motion stops when the electric field created by the separated charges creates an equal and opposite force to the magnetic force created by the rod's motion.
The motion stops when the electric field created by the separated charges creates an equal and opposite force to the magnetic force created by the rod's motion.
The separated charge creates a potential 
Example Question #1 : Electricity And Magnetism
Suppose that a proton moves perpendicularly through a magnetic field at a speed of 
To solve this question, we need to relate the speed and charge of the particle with the magnetic force it experiences in order to solve for the magnetic field strength. Thus, we'll need to use the following equation:
Also, we are told that the particle is moving perpendicularly to the magnetic field.
Rearrange to solve for the magnetic field, then plug in known values and solve.
Example Question #2 : Magnetic Fields
Suppose that a positively charged particle with charge 
To answer this question, we need to realize that the particle is moving in a circular path because of some sort of centripetal force. Since the charge is moving while within a constant magnetic field, we can conclude that it is the magnetic force that is responsible for the centripetal force that keeps this charge moving in a circle. Thus, we need to relate the centripetal force to the magnetic force.
The above equation shows us that the radius of the circular path is directy proportional to the mass and velocity of the particle, and inversely proportional to the charge of the particle and the magnetic field strength. Thus, if the value of the magnetic field is doubled, the above equation predicts that the value of the radius would be cut in half.
Example Question #1 : Magnetism And Electromagnetism
Using:
Where:
Plugging in values:
Example Question #1 : Electricity And Magnetism
There is a loop with a radius of 
None of these
Using the Biot-Savart law:
Where 
Plugging in values:
Example Question #1 : Magnetic Fields
A circular circuit is powered by a 
None of these
The magnetic field will become zero
The magnetic field will have the same magnitude and direction
The magnetic field will have the same magnitude, albeit in the opposite direction
The magnetic field will double in magnitude and flip directions
The magnetic field will have the same magnitude, albeit in the opposite direction
Reversing the battery will reverse the direction of the current. Using the right hand rule, it can be seen that this will also reverse the direction of the magnetic field. Since the magnitude of the current stays the same, the magnitude of the magnetic field will as well.
Example Question #1 : Magnetism And Electromagnetism
A circular circuit is powered by a 
The magnetic field will quadruple
The magnetic field will stay the same
The magnetic field will double in magnitude and have the same direction.
The magnetic field will become zero
None of these
The magnetic field will double in magnitude and have the same direction.
Based on the Biot-Savart law:
Doubling the voltage will double the current, which will double the magnetic field. The direction will stay the same.
Example Question #1 : Magnetic Fields
If the north end of a magnetic points towards the geographic north pole, that means that the geographic north pole is a magnetic __________ pole.
Mono
South
Electrical
North
None of these
South
Magnets will align themselves with the surrounding magnetic field. Thus, if the north pole of a magnet is pointing north, the direction of the magnetic field must be pointing north. Magnetic fields point towards magnetic south poles, so the geographic north pole is actually a magnetic south pole.
Example Question #8 : Magnetic Fields
An infinitely long wire carries a current of 
None of these
Magnetic field of an infinitely long wire:
Where
Plugging in values:
Example Question #11 : Magnetism And Electromagnetism
A circuit contains a 
None of these
Using
Converting 
Determining current:
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