Question on Optics, finding images of a pin using a concave mirror

In summary, the conversation discusses the placement of a 1cm long pin at an angle in front of a concave mirror with a focal length of 5cm. The point B lies on the principal axis at a distance of 4cm and the point A is at an angle of 60° from point P, the pole. The goal is to find the positions of A' and B' of the needle's image, determine the image's nature and magnification. The image is determined to be virtual, erected and magnified with a magnification of 3. The conversation also includes a request for a work solution to find the position and size of the image of point A, which is at the peak of the red arrow in
  • #1
Krishna0703
15
0
A pin AB, 1cm long, is placed at an angle to the principal axis in front of a concave mirror, of focal length 5cm. Point B lies on the principal axis at a distance of 4 cm. Point A is such that the angle ABP is 60°, where P, the pole, is the point where the principal axis intersects the mirror.



a.) Find the positions of A' and B' of the needle's image.
b.) Determine the image's nature and magnification.


I have attempted to the solution but still i feel am in a sort of foolish mistakes...would be grateful if anyone can help me please. after going through the physics, i am sure and convinced that the image is an erected, magnified and virtual now...and obtained magnification as 3. part a.) of the question is unsure...can u help with an answer please...
 
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  • #2
Hi, Krishna,

Can you show a picture, and your work, please? You must be on the right track, as the image is virtual. ehild
 
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  • #3
sure...i will take a snap of it and share it here..can u download the files please..then u zoom on it for better view...sorry for the scrap i written...but am a poor student...that already embarrasses me
 

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  • #4
Is the magnification not defined as the seize of the image divided by the seize of the object ?

I do not see if you did anything to find the image of A. See my drawing.
What is the object distance for the red object? Note, that the length of the pinl=1 cm. Find the position of A' and determine the length A1B' to get the magnification.

ehild
 

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  • #5
can u help me with a work solution for this time please?
 
  • #6
I do not understand what is a work solution you expect from me. I am just trying to help. The point A is at the peak of the red arrow in my previous picture. Determine the position and size of the image of the red arrow: Its peak is the image of A.
For that, you need the object distance, do, it is shorter than it was for B. Therefore, the magnification will be different for A and B.

ehild
 
  • #7
okki, i got it, am off to my desk to work it out ehild..thanks.
 

Related to Question on Optics, finding images of a pin using a concave mirror

1. How does a concave mirror form images of a pin?

A concave mirror forms images of a pin by reflecting light rays from the pin onto a focal point in front of the mirror. This is known as a real image, where the light rays actually converge to form an image.

2. What is the difference between a real and virtual image in optics?

A real image is formed when light rays actually converge to form an image, while a virtual image is formed when light rays only appear to converge due to the reflection or refraction of light. Real images can be projected onto a screen, while virtual images cannot.

3. How do you find the location of an image formed by a concave mirror?

The location of an image formed by a concave mirror can be found using the mirror equation: 1/f = 1/o + 1/i, where f is the focal length, o is the object distance, and i is the image distance. Plug in the known values and solve for i to find the location of the image.

4. Can a concave mirror produce both real and virtual images?

Yes, a concave mirror can produce both real and virtual images. It depends on the location of the object relative to the focal point and mirror. Objects placed beyond the focal point will produce real images, while objects placed between the focal point and mirror will produce virtual images.

5. How does the size of an image formed by a concave mirror compare to the size of the object?

The size of the image formed by a concave mirror can vary depending on the location of the object. If the object is placed between the focal point and mirror, the image will be larger than the object. If the object is placed beyond the focal point, the image will be smaller than the object. This is known as magnification and can be calculated using the equation M = -i/o, where M is the magnification, i is the image distance, and o is the object distance.

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