How does Change in Speed result in Change of Direction of Light? | Don't Memorise

TL;DR

Refraction of light occurs when light travels from one medium to another, causing a change in speed and direction.

Transcript

in the previous video we learned what refraction of light is refraction of light is a transmission of light through an object in which the light which is incident obliquely bends at the boundary of the two media we also said that the bending of light in the medium is caused by the change in its speed when light is traveling from an optically rarer ... Read More

Key Insights

• 🙂 Refraction of light occurs when light moves from one medium to another, resulting in a change in speed and direction.
• 🔉 The change in speed of light in different media causes it to bend towards or away from the normal, depending on the optical density of the medium.
• 🛒 The analogy of a shopping cart moving from one surface to another helps visualize and understand the concept of light refraction.
• 💱 The direction of light only changes when it enters the boundary between media obliquely; perpendicular incidence results in a change of speed but not direction.
• 🔉 Light travels more easily in optically rarer media, leading to its direction being away from the normal in the refractive medium.
• 🔉 The speed of light increases when it travels from an optically denser medium to an optically rarer medium.
• 🚄 The shopping cart analogy demonstrates that entering a medium with higher friction causes a decrease in speed, while entering a medium with lower friction increases speed.

Questions & Answers

Q: How does the change in speed affect the direction of light in refraction?

The change in speed of light when it passes from one medium to another results in the bending of light. When light travels from an optically rarer to a denser medium, its speed decreases and it bends towards the normal. Conversely, when light travels from an optically denser to a rarer medium, its speed increases and it bends away from the normal.

Q: Can the analogy of a shopping cart moving from one surface to another help understand light refraction?

Yes, the analogy of a shopping cart moving from a concrete road to grass can help understand light refraction. When the cart enters the grass surface, its speed reduces due to increased resistance, similar to how light slows down when entering an optically denser medium. The change in speed causes the cart, and light, to change direction.

Q: Does light always change direction when it undergoes refraction?

No, the direction of light only changes when it moves obliquely through the boundary of two media. When light enters a medium perpendicular to the surface, its speed may increase or decrease, but its direction remains unchanged.

Q: What happens when light travels from an optically denser medium to an optically rarer medium?

When light travels from an optically denser medium to an optically rarer medium, its speed increases. This causes the light to bend away from the normal, maintaining its direction but changing its speed.

Summary & Key Takeaways

• Refraction of light is the bending of light as it passes from one medium to another, caused by a change in speed.

• The change in speed of light when it travels from an optically rarer medium to an optically denser medium causes it to bend towards the normal.

• When light travels from an optically denser medium to an optically rarer medium, its speed increases and it bends away from the normal.