Lecture Notes Video Flashcards: Physics Review (EM, Optics, Electricity & Magnetism, Modern Physics)

A comprehensive set of practice flashcards derived from the provided lecture notes, covering topics in optics, electromagnetism, circuits, and modern physics.

In empty space, which quantity is always larger for X-ray radiation than for a radio wave?

Frequency

If the Earth–Sun distance were doubled, the intensity of radiation from the Sun that reaches the Earth’s surface would?

Drop to 1/4

Which will produce an EM wave?

An alternating current

What is the unit of magnetic field?

T (Tesla)

Which of the following do not produce magnetic fields?

Stationary objects that have electric charge and changing electric fields

If the intensity of an electromagnetic wave doubles, how should both the magnetic field and the electric field change?

Increase by a factor of √2

Suppose you are standing about 3m in front of a mirror. If you walk one step closer to the mirror you will not be able to see any more of your image. Why?

Because of the mirror's limited view range

Minimum size of a mirror to see yourself full-length?

Half height and half body width

Why does light come out the end of an optical fiber but not out both sides?

Total internal reflection

Where should you aim to shoot a swimming fish with a laser?

Slightly below the image

Where are images formed?

At the point where light rays from a point object cross

Cause of the colors in a rainbow?

Different refraction for different colors

When does destructive interference occur with thin glass and air?

When air is replaced with water, destructive interference still occurs

Difference in interference pattern with soap film in air versus water?

No difference

Why light spreads out instead of traveling straight through a narrow slit?

Light is a wave; this is a basic wave property

Two waves are out of phase by how many degrees?

90 degrees

Effect of increased wavelength in a double slit experiment?

Interference pattern spreads out

Which case allows light to get through three polarizers?

Case 2 only

Mass and charge comparison between Fred and Jane, the lightning bugs?

Attracted equally towards each other

True statement about a negative point charge in an electric field?

Field points away from the positive charge, force is opposite

Meeting point of a proton and an electron released from rest one meter apart?

Closer to the proton's original position

Force on charge Q1 due to Q2 at origin, with Q1 = -0.10 µC, Q2 = +0.10 µC at x=1m?

Attractive, in the +x-direction

Order: Field strength at point 1 compared to point 2 based on electric field lines?

Larger at point 1 (closer field lines)

Best safety measure in lightning storm?

Inside a metal car

Correct statement using Gauss’s law for non-conducting object?

Gauss’s law is true but not useful here

If point charge is at center of hollow metal sphere with opposite charge, what is true between sphere and point charge?

Electric field only due to point charge

Electric flux exiting bag with charged flies?

Total electric flux is zero (flies have equal and opposite charges)

Effect on electric field strength if Earth’s charge distributed on Moon?

16 E (Moon's radius is 1/4 of Earth's)

Charge in Gauss’s law to calculate electric field at point A in figure?

-3C (outer shell total charge)

Electric field and potential at midpoint of two identical positive charges?

Electric field is zero, potential is positive

Valid statement about electric potential in a region?

If potential is constant, field must be zero

Work to move three +q point charges from infinity to a distance d apart compared to two charges?

3W

Effect of replacing +0.2 µC charge in uniform field with -0.2 µC charge?

Electric potential stays same, potential energy changes sign

Electric potential at points A, B, C, D, E in uniform field?

Largest at point A

Potential and potential energy comparison for charges +q and +2q at distance r from plate holding charge +Q?

Same potential, different potential energy

What happens when parallel-plate capacitor plates are pulled closer while connected to a voltage source?

Charge constant, voltage decreases

Change in energy stored in capacitor if voltage changes from V to 2V?

Energy becomes 4U

Capacitors with same charge: which has larger potential difference?

One with smaller capacitance

Effect on electric field when plates of capacitor are pulled apart while voltage is constant?

Gradually decreases

Effect of reversing battery on lightbulb brightness?

Glows with same brightness

True statement about Ohm’s law?

Relates current through a wire to voltage across it

Reason circuit breaker opens with too many devices?

Current becomes too high

Reason light comes on immediately when switch is turned on?

Electrons in wire are instantly “pushed” by voltage difference

Unit kilowatt-hour measures what?

Amount of energy

Effect on power dissipation if resistance in a circuit is doubled while constant voltage applied?

Power reduced by factor of 2

Current through resistors when 10,000 Ω and 100 Ω resistors swapped in series?

10 A

Which resistors are connected in parallel?

R1 and R3

What happens to voltage across R4 when switch is closed?

It will decrease

Resistor with greatest current if all have same resistance R?

R5

Time to discharge capacitor to 1/4 Q0 if 1/2 Q0 takes 2.0 seconds?

4 seconds

Resistance for ammeters and voltmeters to not alter measurements?

Ammeter must have very low resistance; voltmeter very high resistance

Cutting a bar magnet to create two poles; which cut meets request for stronger north pole?

No cut can achieve this

Field created by moving proton?

Both electric and magnetic fields

Path of charged particle moving parallel to magnetic field direction?

Travels in straight line

Effect of perpendicular magnetic field on proton's kinetic energy?

Stays the same

Magnetic field direction at point when current in wire points into the page?

Direction C

Use of constant magnetic field with charged particle?

Only changes direction of particle’s velocity

Direction of lower wire current for horizontal current-carying wires?

Opposite to direction in upper wire

Magnitude of forces exerted by parallel 10-A and 5-A currents on each other?

Same force on each other

Magnetic field inside thick copper wire carrying DC current?

Strongest just inside surface, zero at center

Region with lowest magnetic field magnitude for concentric pipes carrying opposite currents?

Regions a, b, e

Effect on B inside long solenoid if length and number of loops doubled?

No change

Constant velocity of wire loop moving through constant magnetic field: induced current?

Zero

Is current induced when loop moves parallel to wire in Figure 29-45?

No

What can a good transformer accomplish?

Changing both current and voltage

What induces current in second coil of wire with changing current in first coil?

Change in current in first coil

Best wire shape to obtain greatest self-inductance with 1.0 m wire?

Many tiny loops

Most significant increase to period of oscillating LC circuit?

Double both inductance and capacitance

In an oscillating LC circuit, what oscillates?

All quantities oscillate (charge, current, etc.)

True about all series AC circuits?

Current same at any point in circuit

Action to always increase rms current in LRC series AC circuit?

Increase source voltage

Condition for minimum impedance in LRC circuit?

At resonance

What causes lines seen between fingers when looking at bright light?

Diffraction pattern

Main reason sound waves bend around corners compared to light waves?

Sound has longer wavelengths that bend more

Effect of increasing slit width by 20% in diffraction pattern?

Pattern spacing compressed

Condition to retain original diffraction pattern when replacing blue light with red light?

Change slit width to 2D for red light

Determinant of smallest object clear to naked eye?

Pupil diameter

Effect on central bright fringe width if slit width reduced?

Becomes wider

Proper length of rocket measured at 0.5c compared to at rest?

Measured shorter at speed; proper length at rest is 50 m

Speed of light measured by technicians on ship B from ship A's headlight?

1.0 c

Observer effect on pendulum period in spaceship moving at 0.6c compared to parked on Earth?

More than 2 s (time dilation)

Validity of relativistic formulas for all speeds?

Valid for all speeds

Check for spaceship rest or constant velocity with no external reference?

Can't tell

Photon energy comparison from violet to red light?

Violet photon has more energy

Possibility of no electron ejection from metal with lower photon energy?

Energy less than the threshold might not eject electrons

Electron behavior based on experiment?

Exhibits either particle or wave properties

Photon count comparison for equal intensity red and blue light beams?

More photons in red beam

De Broglie wavelength of thrown baseball compared to atom size?

Much smaller than the nucleus