Focal Length - Revision history

NRJC: /* About Focal Length */

2019-12-19T08:26:09Z

‎About Focal Length

Ellen References at 08:11, 7 December 2019

2019-12-07T08:11:08Z

Ellen References at 10:45, 20 November 2019

2019-11-20T10:45:28Z

Ellen References at 16:18, 15 November 2019

2019-11-15T16:18:54Z

NRJC: Created page with "==Key Stage 4 Higher== ===Meaning=== The '''focal length''' of a lens is the distance between the lens and the focussed image of a "distant object". ===Ab..."

2019-02-24T13:26:27Z

Created page with "==Key Stage 4 Higher== ===Meaning=== The '''focal length''' of a lens is the distance between the lens and the focussed image of a "distant object". ===Ab..."

New page

==Key Stage 4 Higher==
===Meaning===
The '''focal length''' of a [[lens]] is the [[distance]] between the [[lens]] and the [[focus]]sed [[image]] of a "distant object".

===About Focal Length===
{| class="wikitable"
|-
|[[File:ConvexLensFocalPoint.png|center|500px]]
|-
| style="height:20px; width:200px; text-align:center;" |A '''convex lens''' [[focus|focuses]] [[parallel]] [[Light Ray|rays]] to a [[Focal Point|focal point]].
|}
: The [[Focal Length|focal length]] of a '''convex lens''' is the distance between the [[Focal Point|focal point]] and the centre of the [[lens]].
{| class="wikitable"
|-
|[[File:FocalLength.png|center|500px]]
|-
| style="height:20px; width:200px; text-align:center;" |A [[diagram]] showing how to find the [[Focal Length|focal length]] of a '''convex [[lens]]'''.
|}
To find the [[Focal Length]] of a '''convex [[lens]]''':
*[[Focus]] the [[image]] of a "distant object" onto a [[screen]].
*[[Measure]] the [[distance]] between the [[lens]] and the [[screen]].
: The [[Image Distance|image distance]] (the distance between the [[focus]]sed [[image]] and the [[lens]]) is the same as the [[Focal Length|focal length]] for a "distant object".
: If the [[Object Distance|object distance]] (the distance between an [[object]] and a [[lens]]) is too small, then the [[Focal Length|focal length]] is not the same as the [[Image Distance|image distance]].

← Older revision		Revision as of 08:11, 7 December 2019
Line 34:		Line 34:

	:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Focal length, pages 119, 121, GCSE Physics, CGP, Edexcel '']		:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Focal length, pages 119, 121, GCSE Physics, CGP, Edexcel '']
		+
		+	====OCR====
		+	:[https://www.amazon.co.uk/gp/product/0198359837/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359837&linkCode=as2&tag=nrjc-21&linkId=3c4229e8b023b2b60768e7ea2307cc6f ''Focal length, pages 162, Gateway GCSE Physics, Oxford, OCR '']

← Older revision		Revision as of 10:45, 20 November 2019
Line 30:		Line 30:
	:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Focal length, pages 208-211, GCSE Physics; Third Edition, Oxford University Press, AQA '']		:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Focal length, pages 208-211, GCSE Physics; Third Edition, Oxford University Press, AQA '']
	:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Focal length, pages 266, 267, 272, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']		:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Focal length, pages 266, 267, 272, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']
		+
		+	====Edexcel====
		+
		+	:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Focal length, pages 119, 121, GCSE Physics, CGP, Edexcel '']

← Older revision		Revision as of 16:18, 15 November 2019
Line 22:		Line 22:
	: The [[Image Distance\|image distance]] (the distance between the [[focus]]sed [[image]] and the [[lens]]) is the same as the [[Focal Length\|focal length]] for a "distant object".		: The [[Image Distance\|image distance]] (the distance between the [[focus]]sed [[image]] and the [[lens]]) is the same as the [[Focal Length\|focal length]] for a "distant object".
	: If the [[Object Distance\|object distance]] (the distance between an [[object]] and a [[lens]]) is too small, then the [[Focal Length\|focal length]] is not the same as the [[Image Distance\|image distance]].		: If the [[Object Distance\|object distance]] (the distance between an [[object]] and a [[lens]]) is too small, then the [[Focal Length\|focal length]] is not the same as the [[Image Distance\|image distance]].
		+
		+	===References===
		+	====AQA====
		+
		+	:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Focal length, page 204, GCSE Physics, Hodder, AQA '']
		+	:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac178 ''Focal length, page 82, GCSE Physics; The Revision Guide, CGP, AQA '']
		+	:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Focal length, pages 208-211, GCSE Physics; Third Edition, Oxford University Press, AQA '']
		+	:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Focal length, pages 266, 267, 272, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']

@@ Line 20: / Line 20: @@
 *[[Focus]] the [[image]] of a "distant object" onto a [[screen]].
 *[[Measure]] the [[distance]] between the [[lens]] and the [[screen]].
-: The [[Image Distance|image distance]] (the distance between the [[focus]]sed [[image]] and the [[lens]]) is the same as the [[Focal Length|focal length]] for a "distant object".
-: If the [[Object Distance|object distance]] (the distance between an [[object]] and a [[lens]]) is too small, then the [[Focal Length|focal length]] is not the same as the [[Image Distance|image distance]].
+The [[Image Distance|image distance]] (the distance between the [[focus]]sed [[image]] and the [[lens]]) is the same as the [[Focal Length|focal length]] for a "distant object".
 ===References===