Waves and Electromagnetic Radiation - Revision history

Conrad: Remove the Rows section (anchor names are documented on Template:Rt)

2026-10-25T21:52:22Z

Remove the Rows section (anchor names are documented on Template:Rt)

Conrad: Row anchors as zero-height blocks above the image, so a row link shows the whole table

2026-10-25T21:41:17Z

Row anchors as zero-height blocks above the image, so a row link shows the whole table

Conrad: Show the official table image instead of a wikitext copy; row anchors now land on the image

2026-10-25T21:40:05Z

Show the official table image instead of a wikitext copy; row anchors now land on the image

Conrad: Make the Regents Exam Questions table scroll sideways on narrow screens instead of widening the page

2026-10-25T21:31:30Z

Make the Regents Exam Questions table scroll sideways on narrow screens instead of widening the page

Conrad: Physics reference tables (2025 Edition): new reference table page

2026-10-25T20:28:22Z

Physics reference tables (2025 Edition): new reference table page

New page

{{Physreftable
|name=Waves and Electromagnetic Radiation
|prev=Energy
|next=The Electromagnetic Spectrum (Physics)
|desc=Waves and Electromagnetic Radiation equations from the NYS Physics Reference Tables (2025 Edition): wave speed v = f lambda, period, photon energy E = hf, the law of reflection, index of refraction, Snell's law, the lens equation and magnification, with their variables.
}}
The '''Waves and Electromagnetic Radiation''' page of the ''Reference Tables for Physical Science: Physics'' (2025 Edition) is the waves and optics equation sheet: nine equations with the meaning of their variables. Wave speed, period, index of refraction and Snell's law support [[HS-PS4-1]]; ''E''photon = ''hf'' supports [[HS-PS4-3]] and [[HS-PS4-4]] (and the physics side of [[HS-ESS1-2]]); the law of reflection, the lens equation and magnification support [[HS-PS4-6]]. Every equation has its own row anchor.

<div style="display:flex;flex-wrap:wrap;gap:16px 32px;align-items:flex-start;">
<div style="min-width:0;">
{| class="wikitable" style="text-align:center;"
! Equations
|- id="wave-speed"
| style="padding:8px 16px;" | ''v'' = ''f''λ
|- id="period"
| style="padding:8px 16px;" | ''T'' = 1''f''
|- id="photon-energy"
| style="padding:8px 16px;" | ''E''photon = ''hf''
|- id="reflection"
| style="padding:8px 16px;" | θi = θr
|- id="index-of-refraction"
| style="padding:8px 16px;" | ''n'' = ''c''''v''
|- id="snell"
| style="padding:8px 16px;" | ''n''1 sin θ1 = ''n''2 sin θ2
|- id="index-ratio"
| style="padding:8px 16px;" | ''n''2''n''1 = ''v''1''v''2 = λ1λ2
|- id="lens-equation"
| style="padding:8px 16px;" | 1''F'' = 1''d''o + 1''d''i
|- id="magnification"
| style="padding:8px 16px;" | ''h''i''h''o = −''d''i''d''o
|}
</div>
<div style="min-width:0;">
{| class="wikitable"
! Variables
|-
| ''c'' = speed of light in a vacuum
|-
| ''d''i = distance to image
|-
| ''d''o = distance to object
|-
| ''E''photon = energy of photon
|-
| ''F'' = focal length
|-
| ''f'' = frequency
|-
| ''h'' = Planck's constant
|-
| ''h''i = image height
|-
| ''h''o = object height
|-
| ''n'' = absolute index of refraction
|-
| ''T'' = period
|-
| ''v'' = velocity ''or'' speed
|-
| λ = wavelength
|-
| θ = angle
|-
| θi = angle of incidence
|-
| θr = angle of reflection
|}
</div>
</div>

== What the waves page shows ==
'''Waves.''' ''v'' = ''f''λ relates the speed, frequency and wavelength of any wave; for light and other electromagnetic waves in a vacuum ''v'' is ''c'' from the [[List of Physical Constants#speed-of-light|List of Physical Constants]], and for sound in air the constants list gives 331 m/s. ''T'' = 1/''f'' converts between period and frequency.

'''Photons.''' ''E''photon = ''hf'' gives the energy of a photon from its frequency, with Planck's constant from the constants list; the [[List of Physical Constants#electronvolt|electronvolt]] entry converts the answer to eV. There is no ''E'' = ''hc''/λ on the tables, so a wavelength has to go through ''v'' = ''f''λ first. This is the only modern-physics equation on the 2025 tables: the 2006 edition's ''E'' = ''mc''2, the energy-level diagrams and the standard-model tables are gone.

'''Reflection and refraction.''' θi = θr is the law of reflection. ''n'' = ''c''/''v'' defines the absolute index of refraction, ''n''1 sin θ1 = ''n''2 sin θ2 is Snell's law, and the ratio equation says that when light enters a medium of higher index its speed and wavelength drop in the same proportion while its frequency stays the same. The 2006 edition's table of indices of refraction is not in the 2025 edition, so a question gives the indices it needs.

'''Lenses and mirrors.''' 1/''F'' = 1/''d''o + 1/''d''i relates the focal length to the object and image distances, and ''h''i/''h''o = −''d''i/''d''o gives the magnification; the minus sign means a real image (positive ''d''i) is inverted. These two equations are new in the 2025 edition, for [[HS-PS4-6]].

== Rows ==
Each row of the table has an anchor, so a link or an <code><nowiki>{{Rt}}</nowiki></code> chip ([[Template:Rt]]) can point at one equation or constant:
* <code>wave-speed</code> – ''v'' = ''f''λ
* <code>period</code> – ''T'' = 1/''f''
* <code>photon-energy</code> – ''E''photon = ''hf''
* <code>reflection</code> – θi = θr
* <code>index-of-refraction</code> – ''n'' = ''c''/''v''
* <code>snell</code> – ''n''1 sin θ1 = ''n''2 sin θ2
* <code>index-ratio</code> – ''n''2/''n''1 = ''v''1/''v''2 = λ1/λ2
* <code>lens-equation</code> – 1/''F'' = 1/''d''o + 1/''d''i
* <code>magnification</code> – ''h''i/''h''o = −''d''i/''d''o

== Regents Exam Questions ==
Released Regents questions that cannot be answered without this table, listed by exam. Each link opens the question with its answer key; the standard is the one the question assesses.

{| class="wikitable" style="width:100%; text-align:center"
! style="padding: 0.5em 1.5em;" | Exam
! style="padding: 0.5em 1.5em;" | Cluster
! style="padding: 0.5em 1.5em;" | Question
! style="padding: 0.5em 1.5em;" | Standard
! style="padding: 0.5em 1.5em;" | Row
|-
| rowspan="6" style="background-color:white;" | [[June 2026 Physics Exam|June 2026 Physics Regents]]
| style="background-color:white;" | [[Questions:Kidney Stone Detection and Removal|Kidney Stone Detection and Removal]]
| style="background-color:white;" | [[Questions:Kidney Stone Detection and Removal#q2|Question 7]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''v'' = ''f''λ
|-
| style="background-color:white;" | [[Questions:Kidney Stone Detection and Removal|Kidney Stone Detection and Removal]]
| style="background-color:white;" | [[Questions:Kidney Stone Detection and Removal#q5|Question 10]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''E''photon = ''hf''
|-
| style="background-color:white;" | [[Questions:Emission Spectra and Nuclear Fusion|Emission Spectra and Nuclear Fusion]]
| style="background-color:white;" | [[Questions:Emission Spectra and Nuclear Fusion#q2|Question 22]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''E''photon = ''hf''; ''v'' = ''f''λ
|-
| style="background-color:white;" | [[Questions:The Cell Phone|The Cell Phone]]
| style="background-color:white;" | [[Questions:The Cell Phone#q2|Question 26]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''n'' = ''c''/''v''
|-
| style="background-color:white;" | [[Questions:Flashlight Physics|Flashlight Physics]]
| style="background-color:white;" | [[Questions:Flashlight Physics#q2|Question 31]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''v'' = ''f''λ
|-
| style="background-color:white;" | [[Questions:Voice Recognition Software|Voice Recognition Software]]
| style="background-color:white;" | [[Questions:Voice Recognition Software#q4|Question 44]]
| style="background-color:white;" | [[HS-PS4-1]]
| style="background-color:white;" | ''T'' = 1/''f''
|-
| rowspan="2" style="background-color:white;" | [[Physics Sample Question Clusters|Physics sample clusters]] (spring 2025)
| style="background-color:white;" | [[Questions:Sampler Automotive Optics|Automotive Optics]]
| style="background-color:white;" | [[Questions:Sampler Automotive Optics#q2|Question 2]]
| style="background-color:white;" | [[HS-PS4-6]]
| style="background-color:white;" | θi = θr
|-
| style="background-color:white;" | [[Questions:Sampler Automotive Optics|Automotive Optics]]
| style="background-color:white;" | [[Questions:Sampler Automotive Optics#q4|Question 4]]
| style="background-color:white;" | [[HS-PS4-6]]
| style="background-color:white;" | ''h''i/''h''o = −''d''i/''d''o
|}

@@ Line 7: / Line 7: @@
 The '''Waves and Electromagnetic Radiation''' page of the ''Reference Tables for Physical Science: Physics'' (2025 Edition) is the waves and optics equation sheet: nine equations with the meaning of their variables. Wave speed, period, index of refraction and Snell's law support [[HS-PS4-1]]; ''E''<sub>photon</sub> = ''hf'' supports [[HS-PS4-3]] and [[HS-PS4-4]] (and the physics side of [[HS-ESS1-2]]); the law of reflection, the lens equation and magnification support [[HS-PS4-6]]. Every equation has its own row anchor.
-<span id="wave-speed"></span><span id="period"></span><span id="photon-energy"></span><span id="reflection"></span><span id="index-of-refraction"></span><span id="snell"></span><span id="index-ratio"></span><span id="lens-equation"></span><span id="magnification"></span>[[File:Waves and Electromagnetic Radiation.png|760px|class=img-fluid|alt=Waves and Electromagnetic Radiation from the Physics Reference Tables (2025 Edition)]]
+<div id="wave-speed"></div><div id="period"></div><div id="photon-energy"></div><div id="reflection"></div><div id="index-of-refraction"></div><div id="snell"></div><div id="index-ratio"></div><div id="lens-equation"></div><div id="magnification"></div>
 == What the waves page shows ==

← Older revision		Revision as of 21:52, 25 October 2026
Line 18:		Line 18:

	'''Lenses and mirrors.''' 1/''F'' = 1/''d''<sub>o</sub> + 1/''d''<sub>i</sub> relates the focal length to the object and image distances, and ''h''<sub>i</sub>/''h''<sub>o</sub> = −''d''<sub>i</sub>/''d''<sub>o</sub> gives the magnification; the minus sign means a real image (positive ''d''<sub>i</sub>) is inverted. These two equations are new in the 2025 edition, for [[HS-PS4-6]].		'''Lenses and mirrors.''' 1/''F'' = 1/''d''<sub>o</sub> + 1/''d''<sub>i</sub> relates the focal length to the object and image distances, and ''h''<sub>i</sub>/''h''<sub>o</sub> = −''d''<sub>i</sub>/''d''<sub>o</sub> gives the magnification; the minus sign means a real image (positive ''d''<sub>i</sub>) is inverted. These two equations are new in the 2025 edition, for [[HS-PS4-6]].
−
−	~~== Rows ==~~
−	~~A link or an <code><nowiki>{{Rt}}</nowiki></code> chip ([[Template:Rt]]) can point at one equation or constant with these anchors; each one lands on the table above:~~
−	* <code>wave-speed</code> – ''v'' = ''f''λ
−	* <code>period</code> – ''T'' = 1/''f''
−	* <code>photon-energy</code> – ''E''<sub>photon</sub> = ''hf''
−	* <code>reflection</code> – θ<sub>i</sub> = θ<sub>r</sub>
−	* <code>index-of-refraction</code> – ''n'' = ''c''/''v''
−	* <code>snell</code> – ''n''<sub>1</sub> sin θ<sub>1</sub> = ''n''<sub>2</sub> sin θ<sub>2</sub>
−	* <code>index-ratio</code> – ''n''<sub>2</sub>/''n''<sub>1</sub> = ''v''<sub>1</sub>/''v''<sub>2</sub> = λ<sub>1</sub>/λ<sub>2</sub>
−	* <code>lens-equation</code> – 1/''F'' = 1/''d''<sub>o</sub> + 1/''d''<sub>i</sub>
−	* <code>magnification</code> – ''h''<sub>i</sub>/''h''<sub>o</sub> = −''d''<sub>i</sub>/''d''<sub>o</sub>

	== Regents Exam Questions ==		== Regents Exam Questions ==

@@ Line 7: / Line 7: @@
 The '''Waves and Electromagnetic Radiation''' page of the ''Reference Tables for Physical Science: Physics'' (2025 Edition) is the waves and optics equation sheet: nine equations with the meaning of their variables. Wave speed, period, index of refraction and Snell's law support [[HS-PS4-1]]; ''E''<sub>photon</sub> = ''hf'' supports [[HS-PS4-3]] and [[HS-PS4-4]] (and the physics side of [[HS-ESS1-2]]); the law of reflection, the lens equation and magnification support [[HS-PS4-6]]. Every equation has its own row anchor.
-<div style="display:flex;flex-wrap:wrap;gap:16px 32px;align-items:flex-start;">
+<span id="wave-speed"></span><span id="period"></span><span id="photon-energy"></span><span id="reflection"></span><span id="index-of-refraction"></span><span id="snell"></span><span id="index-ratio"></span><span id="lens-equation"></span><span id="magnification"></span>[[File:Waves and Electromagnetic Radiation.png|760px|class=img-fluid|alt=Waves and Electromagnetic Radiation from the Physics Reference Tables (2025 Edition)]]
 == What the waves page shows ==
@@ Line 80: / Line 19: @@
 == Rows ==
-Each row of the table has an anchor, so a link or an <code><nowiki>{{Rt}}</nowiki></code> chip ([[Template:Rt]]) can point at one equation or constant:
+A link or an <code><nowiki>{{Rt}}</nowiki></code> chip ([[Template:Rt]]) can point at one equation or constant with these anchors; each one lands on the table above:
 * <code>wave-speed</code> – ''v'' = ''f''λ
 * <code>period</code> – ''T'' = 1/''f''

@@ Line 94: / Line 94: @@
 Released Regents questions that cannot be answered without this table, listed by exam. Each link opens the question with its answer key; the standard is the one the question assesses.
 {| class="wikitable" style="width:100%; text-align:center"
 ! style="padding: 0.5em 1.5em;" | Exam
@@ Line 143: / Line 144: @@
 | style="background-color:white;" | ''h''<sub>i</sub>/''h''<sub>o</sub> = −''d''<sub>i</sub>/''d''<sub>o</sub>
 |}