Physics 2 true and false Flashcards
If you place a proton directly on top of an electron, the net charge of the system is zero (q1)
True
In insulated materials, electrons are tightly bound to atoms and are not free to move (q1)
True
Assuming electrons begin to drift to the right, the current points to the left (q5)
True
Current is direction of positive charges
The drift velocity of the electrons in the wire is extremely high (q5)
False
SLOW!
Good conductors have high resistivity (q5)
False
high resistivity=insulator
Equivalent resistance of parallel resistors is always less than either resistor (Q6)
True
Add in series!
DIAGRAM FOR CAPACITOR (q6)
KNOW! :)
Moving magnets near coils of wire can cause charges in those coils to move. (q8)
True
Electromagnitism!
Moving coils of wire near magnets does not cause the charges in the coil to move ( q8)
False
Magnets near wires moving are always creating charge movement
A coil of wire sits in a constant, uniform magnetic field. There is a current in the wire (q8).
False
if the magnetic field is constant, no current.
An inductor and a solenoid are virtually identical (q8)
True
Same thing :)
When potential is applied to an inductor, the effect of the inductor is to slow down the charge in current through the inductor (q9)
True
Back EMF
The RMS voltage is greater than the peak voltage (q9)
False
RMS is the root mean squared AVERAGE! peak is just that: a peak.
The current in a resistor is out of phase with the applied AC voltage (q9)
False
Resistor is IN PHASE!!!
The displacement current between the plates of a capacitor is caused by charges flowing across the plates. (q10)
False
No charges flow directly across the plate
All electromagnetic phenomena can be described with Maxwell’s Equations (q10)
True
X-Rays have longer wavelengths than visible light (q10)
False
A diverging lens always produces a real image of an object placed in front of it. (q12)
False
True for convex
For an upright image, the magnification is positive; for an inverted image, the magnification is negative. (q12)
True
The Ray Model of Light correctly predicts double-Slit Interference (q13)
False
Because geometry doesn’t work in this scenario
The diffraction of light limits the ability to see small or distance objects. (q13)
True
Electric forces always point parallel to the dirrection of the electric field (t1)
True
Voltage is a measure of potential energy (t1)
False
FIGURE IT OUT
If the total flux through a closed surface is zero, then no electric field exists within the surface (t1)
False
No electric field is founded within the surface
In a parallel plate capacitor, you can think of the energy as being stored in the electric field between the plates (t1)
True
The electric field inside a charged conductor in equilibrium is zero (t1)
True
Doubling the radius of the conducting wire increases its resistance (q1)
False
Inversely related meaning increased cross-section=decreased resistivity.
In typical Materials, heating them up reduces their resistance to charge flow (q1)
False
particles move faster taking up more space.
A single solenoid carrying a current will store magnetic energy (t2)
True
Back EMF caused by magnetism [right hand rule!]
Transformers allow one to change the voltage delivered by an AC supply (t2)
True
ratio of turns to voltage
An RC circuit can be used to create radio waves of a specific frequency (t2)
False
must also have an inductor
The Poynting vector points in the direction of motion of the E-M Wave (t2)
True
The Resistance of two parallel resistors is always more than their sum (t2)
False
A stationary electron in a strong magnetic field will experience acceleration (t2)
False
Only if it already in motion.
Light travels more slowly in glass than air (t3)
True
Light is focused most effectively by spherical mirrors (t3)
False
Parabolic
Dispersion describes the separation of light’s colors by refraction
True
Light rays entering the human eye are primarily bent through refraction into the vitreous humor (the liquid) [t3]
TRUE
Practice test is misleading!
Images are always smaller in convex mirrors
True
Astigmatism describes the aberration caused by different wavelengths focusing to different points. (t3)
False
Different radii of spheres. Differing wavelenths is chromatic
Refraction describes the process of light reflecting off a smooth surface (t3)
False
Reflection is reflecting, refraction is going through
Frequency is unchanged by the medium in which light travels
True
wavelength and speed can change
Two lightbulbs a distance apart will form a pair of coherent light sources (t3)
False
Hard to get coherent light (ex. lasers)
The diffraction of light limits the ability to see small or distant objects
True
It is possible for light to experience total transmission as it is incident on glass from Vacuum
False
All light reflects at least a little bit.
Lateral magnification is m=0.5
False
for flat mirrors m=1
A diffraction grating of 100 slits has greater resolving power than a double-slit grating
True
more is better!
Maxwell claimed that a current is created between the plates of a capacitor by the changing magnetic field
False
Displacement current is created by changing electric fields.
two Wires will be drawn together if they are carrying current in the same direction
True
Right hang rule
Typical resistors are limited in how much current they can conduct
True
Resistors can burn out!
Transformers allow one to change the voltage delivered by an AC supply.
True
Ratio of coils for voltage change.
