I'm working through some past papers and came across the question below and I've shown my ray diagrams as the red and blue lines. For the next question I would think that the image is virtual because light has not actually from the image. However the mark scheme says that it is because the two light rays don't join up in the plane mirror, but they do join up in my diagram. Is my diagram wrong and if so, why would the two rays of light not joining give the indication that the image is virtual?
[Physics] How to you tell that the image in a plane mirror is a virtual image from the following ray diagram
reflectionvisible-light
Related Solutions
After reflection the rays seem to be coming in the direction that they would if there were an object on the left.
The brain chooses the most likely cause for the rays to be coming in that direction - and that's that there is an object on the left.
Exactly why it does that is a psychological question, but when humans were evolving mirrors weren't around, although the refraction in water effect, or reflection from still pools could have been seen.
What you have done is correct. We have to judge the diagram by obtaining the results from the formula but not just simply imagining a diagram. The results suggest that your diagram was wrong and the correct diagram could be the below one:
Extending the comments:
To get a real image the virtual object should lie in between pole and the focus. We can prove this result from mirror formula. From the sign conventions, we have $f>0$ ,$u>0$ and $v$ should be less than zero (for forming real image).
So from mirror formula, $ \frac{1}{v}=\frac{1}{f}-\frac{1}{u} <0$ $\implies u<f$
Best Answer
The actual physical light ray doesn't pass through the image so it is virtual.