12 Light

Evan Toh

Oct 251 min read

Various lens experiments

The video below shows a typical lens experiment. (reference to O-Level SciPhy 2015). I will briefly go through the set-up, main steps and...

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Minimum distance h mirror from the floor

Evan Toh

Oct 241 min read

Minimum distance h mirror from the floor

Answer: Option B

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Different Converging Lens Ray Diagram questions

Evan Toh

Oct 241 min read

Different Converging Lens Ray Diagram questions

Drawing ray diagrams for converging lens come in many forms. But the basic concepts needed are the 3 rays (which have rules to follow) to...

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Converging Lens – Which ray is correct after passing through the lens

Evan Toh

Oct 241 min read

Converging Lens – Which ray is correct after passing through the lens

Which of the following light rays behaves correctly when it passes through the converging lens? Solutions: Option C Recall these basic...

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What is Total Internal Reflection (TIR)?

Evan Toh

Oct 211 min read

What is Total Internal Reflection (TIR)?

Overview of Total Internal Reflection (TIR) Explanation of the various stages:

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Main 4 types of images formed by a thin converging lens

Evan Toh

Oct 170 min read

Main 4 types of images formed by a thin converging lens

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Finding focal length f of the lens using pin and mirror or sharp image from distance object

Evan Toh

Sep 302 min read

Finding focal length f of the lens using pin and mirror or sharp image from distance object

A thin convex lens is placed on a plane mirror and an object pin is then moved along the axis of the lens until an image is seen to...

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Light and sound wave diagram in different mediums with different density

Evan Toh

Sep 301 min read

Light and sound wave diagram in different mediums with different density

Light and sound are both waves. So both carry energy from one place to another. Light , which is part of the electromagnetic spectrum,...

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Lens – Complete the rays S and T as they pass through the lens

Evan Toh

Sep 301 min read

Lens – Complete the rays S and T as they pass through the lens

To do similar questions, it is important to know the 3 rays which have rules to follow in order to locate the image. Look through the...

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Light Experiments – Glass Block and Pins

Evan Toh

Aug 311 min read

Light Experiments – Glass Block and Pins

The video include 3 different light experiments which involve glass block and pins. Most students faced difficulties in locating the pins...

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2010SPp1q12 Lens - focal length definition

Evan Toh

Jan 11 min read

2010SPp1q12 Lens - focal length definition

Answer: Option C Focal length f is the distance between the focal point and the centre of the lens (optical centre) . Note that only...

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Total Internal Reflection (TIR) example 01

Evan Toh

Dec 31, 20231 min read

Total Internal Reflection (TIR) example 01

Solutions: a) Refraction b) 48.6o c) c = 41.8o e) 70o d) Total internal reflection has occured, as the angle of incidence is...

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Evan Toh

Dec 31, 20232 min read

Converging Lens Overview

1. Converging lens (convex lens) Converging lens, also known as convex lens, is thicker at the centre. Below shows some examples. In...

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Evan Toh

Dec 31, 20231 min read

Different Lens Ray Diagram questions

Drawing ray diagrams for converging lens come in many forms. But the basic concepts needed are the 3 rays (which have rules to follow) to...

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Pins inside and outside of beaker filled with water – 2012 sciphy practical

Evan Toh

Dec 31, 20231 min read

Pins inside and outside of beaker filled with water – 2012 sciphy practical

A pin in the beaker of water appears higher than its actual position due to refraction of light. In this experiment, you have to adjust...

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Different ways to form a sharp image on a screen through the lens

Evan Toh

Dec 31, 20230 min read

Different ways to form a sharp image on a screen through the lens

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Total Internal Reflection (TIR) basic concepts

Evan Toh

Dec 31, 20230 min read

Total Internal Reflection (TIR) basic concepts

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Identifying what lens, focal length and image from 2 rays – PP2010P1Q23 and SP2014P1Q11

Evan Toh

Dec 31, 20231 min read

Identifying what lens, focal length and image from 2 rays – PP2010P1Q23 and SP2014P1Q11

These 2 questions are actually the same. Q23 is from 2010 Pure Physics P1 while Q11 is from 2014 Sci Physics P1. Take a look at these 2...

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Where is the focal point of lens L1 and L2?

Evan Toh

Dec 31, 20231 min read

Where is the focal point of lens L1 and L2?

Answer: Option A Refer to the diagram (below left) which many are familiar. When parallel rays of light which are parallel to the...

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PP2006P1Q21 SP2009p1q11-how many students can see the images of the other two

Evan Toh

Dec 31, 20231 min read

PP2006P1Q21 SP2009p1q11-how many students can see the images of the other two

Answer: Option D

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