A ray passing through the principal focus of a concave mirror will, after reflection:
emerge parallel to the principal axis
Reflection is reversible: a ray travelling parallel to the principal axis of a concave mirror is reflected through the principal focus, so a ray that arrives along the reverse of that path must leave along the reverse of the first.
A ray directed through the principal focus therefore comes back parallel to the principal axis after reflection. Only a ray aimed at the centre of curvature returns along its own path, since it strikes the mirror along the normal.
Hence, the answer is emerge parallel to the principal axis.
Similar Questions
A ray of light enters a rectangular glass slab from air at an angle of 40 degrees to the normal. If the refractive index of glass with respect to air is 1.5 and the velocity of light in air is \(3 \times 10^{8}\) m/s, what is the velocity of light inside the glass slab?
What happens when white light passes through a glass prism?
A traffic surveillance camera uses a convex mirror with a radius of curvature of 2 m. Where will the image of a car located 3 m from the mirror appear?
During an experiment, a student places a candle beyond twice the focal length of a convex lens and records the image position and nature. Which of the following scenarios could result from this setup?
A student places an object 15 cm in front of a concave mirror of focal length 10 cm. If the image formed is real, what is the magnification produced by the mirror?
How does the size of atmospheric particles affect the scattering of sunlight?
Why does white light split into different colours when passing through a prism but not when passing through a glass slab?
Which of the following statements is FALSE for a converging lens?
A student observes a pencil half-immersed in water (refractive index 1.33) and notices the apparent bending is less than when the pencil is in a liquid with refractive index 1.5. What does this suggest about the relationship between refractive index and light bending?
If an image is formed three times the size of the object and is inverted, what is the possible position of the object with respect to a concave mirror of focal length 10 cm?
Important Questions from Refraction and Reflection
- How can you identify a concave and a convex mirror based on the direction of their reflecting surfaces?
- Stars appear to twinkle in the night sky because ______.
What type of image is always formed by a concave lens, no matter where the object is placed?
- Which of the following is NOT caused by atmospheric refraction?
- According to the sign convention, the height of an erect image formed by a mirror is taken as:
