Magnetism and Electromagnetic Induction
What effect does increasing the speed at which a conductor moves through a uniform magnetic field have on an induced emf, assuming all other factors remain constant?
There is no change in induced emf.
The induced emf decreases.
The direction of induced emf reverses.
The induced emf increases.
What is the SI unit of magnetic flux?
Tesla (T)
Ampere-turns (At)
Weber (Wb)
Henry (H)
Which of the following describes how the wavelength of the visible spectrum correlates with momentum transferring upon reflection?
Longer wavelengths transfer less momentum
Shorter wavelengths transmit equal amounts
No correlation exists between wavelength lengths
Greater momenta correspond to shorter wavelengths
When a conducting loop is placed in a changing magnetic field, which of the following best describes the induced current according to Lenz's Law?
It remains constant irrespective of changes in the external magnetic field.
It flows in a direction that enhances the change in the external magnetic field.
It flows in a direction that creates an electric field opposing the induced emf.
It flows in a direction such that its magnetic field opposes the change in the external magnetic field.
If a loop of wire is rotating in a uniform magnetic field, at what orientation relative to the magnetic field lines is the induced current at its maximum?
When the loop is tilted at 45 degrees with respect to the magnetic field lines.
The orientation does not affect induced current magnitude as long as rotation occurs.
When the plane of the loop is parallel to the magnetic field lines.
When the plane of the loop is perpendicular to the magnetic field lines.
What experimental approach would best isolate factors affecting mutual induction between two coaxial coils when alternating current runs through one coil?
Amperage change primary coil verify reaction secondary coil via light bulb intensity readings correlate results current variation
Vary separation distance between coils keep AC frequency constant; use simple multimeter reading secondary
Rotate only one coil relative other keeping both physical proximity wiring switched regularly analyze phase shifts standard oscilloscope
Adjust AC frequency powering primary coil; use lock-in amplifier measuring secondary voltage; plot output versus frequency; observe resonant peaks indicating maximum mutual induction
What is Lenz's Law best summarized as?
An induced current flows in a direction that opposes the change causing it.
The resistivity of a metal increases linearly with temperature.
An induced emf increases with increasing magnetic field strength.
An induced current flows parallel to its causative motion.

How are we doing?
Give us your feedback and let us know how we can improve
If you have two identical solenoids and pass an increasing current through one, what would be observed in terms of induced current in the second solenoid that is stationary relative to and coaxial with the first?
An induced current supporting the increase flows continuously.
An induced current opposing the increase flows temporarily.
An induced voltage but no current due to infinite resistance.
No induced current because they are identical solenoids.
To minimize energy losses due to resistance when measuring induced currents from a changing magnetic flux, what change should be made to an induction coil wired into a circuit?
Wind more turns tightly on each layer of coil being used in experimentation.
Shorten all connecting wires while maintaining their material and thickness.
Increase wire thickness to double its original diameter.
Replace existing wires with ones having lower electrical resistance.
Which factor does not affect the magnitude of induced electromotive force (EMF) in a coil rotating in a uniform magnetic field?
Number of turns in the coil
Speed of rotation of the coil
Color of the coil
Strength of the magnetic field