We have sent an OTP to your contact. Please enter it below to verify.
Alert
Your message here...
Your notification message here...
For any questions or assistance regarding Customer Support, Sales Inquiries, Technical Support, or General Inquiries, our AI-powered team is here to help!
Listen to a student-teacher conversation explaining the topic in a relatable way.
Signup and Enroll to the course for listening the Audio Lesson
Today, we will start with how images are formed by concave mirrors. Can anyone tell me what happens when an object is placed between the focus and the mirror?
The image formed will be virtual, upright, and enlarged!
Excellent! So when we say the image is virtual, what does that imply about its nature?
It means that the rays of light don't actually meet at the image point; they only appear to diverge from that point.
Correct! Let's apply this understanding to our first exercise. A candle 2.5 cm tall is placed 27 cm in front of a concave mirror with a radius of curvature of 36 cm. Can anyone find out where the image will be?
We can use the mirror equation 1/f = 1/v + 1/u! First, we find f, which is R/2 = 18 cm, so f is -18 cm for a concave mirror.
Right! Now plug in the values.
So we substitute u = -27 cm into the equation. It gives us the image distance v after calculation.
Awesome! Make sure to note whether the image is real or virtual and its size. Always remember to summarize your calculations.
Now, let’s move on to convex lenses. Who can remind us how we calculate magnification with a lens?
We calculate it using the formula m = h'/h, where h' is the height of the image and h is the height of the object.
Great! Let’s apply that to an example. A needle 4.5 cm tall is placed 12 cm from a convex lens whose focal length is 15 cm. How do we find where the image forms?
We need to find the value of v using the lens formula first, right?
Exactly! Now, remember the lens formula: 1/f = 1/v - 1/u. Calculate v and then the magnification!
After substituting, I found that the image is virtual and will be upright.
Excellent application! Always keep in mind that virtual images tend to be magnified by convex lenses.
Let’s discuss refraction. Who can tell me what happens when light passes from air into water?
It bends towards the normal because water is denser than air.
Correct! Now let's consider the angle of incidence and angle of refraction. We can solve a problem where a needle’s depth in water is 12.5 cm, but it appears 9.4 cm deep. What’s the refractive index?
We can use the formula for apparent depth, which is h' = h/n, so rearranging gives n = h/h'.
Exactly right! Now apply it and don’t forget to consider the change when the water is replaced with something else.
I think the refractive index will change, affecting how the needle is viewed in the new liquid.
That’s right! Great job everyone, let’s recap the critical points.
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
The exercises provided in this section aim to reinforce understanding of the principles of reflection and refraction, calculations involving mirrors and lenses, and practical applications of optical phenomena.
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
Image Formation: The process by which an object’s rays converge or diverge to create an image.
Refraction: The bending of light as it passes from one medium to another.
Critical Angle: The angle of incidence above which total internal reflection occurs.
See how the concepts apply in real-world scenarios to understand their practical implications.
Example 1: Calculate the image position when a candle is 27 cm from a concave mirror with a curvature radius of 36 cm.
Example 2: A needle 4.5 cm away from a convex mirror creates a virtual image that is diminished.
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
Light from objects converges near, to form images that are clear.
Imagine a small candlefar from a mirror, reflecting its light bright. When closer, it shows a bigger sight!
ABCDE for the laws of optics: A for Angle of incidence, B for Bends (refraction), C for Critical angle.
Review key concepts with flashcards.
Term
What is Focal Length?
Definition
What does Magnification represent?
Review the Definitions for terms.
Term: Focal Length
Definition:
Distance from the lens or mirror at which parallel rays converge or appear to diverge.
Term: Magnification
Ratio of the height of the image to the height of the object; indicates how much larger an image is as compared to the actual object.
Term: Virtual Image
Image formed where rays appear to diverge; cannot be projected onto a screen.
Term: Real Image
Image formed when rays converge and can be projected onto a screen.
Term: Refractive Index
Measure of how much light bends when entering a material.
Flash Cards
Glossary of Terms