Class 10 science light reflection and refraction notes
Multiple Choice Questions (MCQs)
Q1. The angle of incidence is always equal to the angle of _______.
(a) Refraction
(b) Reflection
(c) Deviation
(d) Dispersion
Ans: (b) Reflection
Q2. Image formed by a plane mirror is –
(a) Real, inverted, same size
(b) Virtual, erect, same size
(c) Real, erect, larger
(d) Virtual, inverted, smaller
Ans: (b) Virtual, erect, same size
Q3. A spherical mirror whose reflecting surface is curved inwards is called –
(a) Convex mirror
(b) Concave mirror
(c) Plane mirror
(d) Cylindrical mirror
Ans: (b) Concave mirror
Q4. For a spherical mirror, the relation between radius of curvature (R) and focal length (f) is –
(a) R = f
(b) R = 3f
(c) R = 2f
(d) R = f/2
Ans: (c) R = 2f
Q5. The distance between pole and focus of mirror is called –
(a) Aperture
(b) Principal axis
(c) Focal length
(d) Radius of curvature
Ans: (c) Focal length
Q6. Concave mirrors are used in –
(a) Rear-view mirrors in vehicles
(b) Solar furnace
(c) Shops for security
(d) Spectacles for short-sightedness
Ans: (b) Solar furnace
Q7. Convex mirrors are preferred as rear-view mirrors because –
(a) They give enlarged image
(b) They give real image
(c) They give erect, diminished and wider view
(d) They give inverted image
Ans: (c) They give erect, diminished and wider view
Q8. A concave mirror forms an enlarged, virtual image when object is placed –
(a) Beyond centre of curvature
(b) At focus
(c) At infinity
(d) Between pole and focus
Ans: (d) Between pole and focus
Q9. The formula ( \frac{1}{f} = \frac{1}{v} + \frac{1}{u} ) is known as –
(a) Lens formula
(b) Mirror formula
(c) Refraction law
(d) Snell’s law
Ans: (b) Mirror formula
Q10. Magnification (m) of a mirror is given as –
(a) v/u
(b) –v/u
(c) f/u
(d) u/v
Ans: (b) –v/u
Q11. When light passes from rarer to denser medium, it bends –
(a) Away from normal
(b) Towards normal
(c) Does not bend
(d) At right angle
Ans: (b) Towards normal
Q12. Which law is also known as Snell’s law?
(a) Law of reflection
(b) Law of diffraction
(c) Law of refraction
(d) Law of interference
Ans: (c) Law of refraction
Q13. A convex lens is also called –
(a) Diverging lens
(b) Converging lens
(c) Cylindrical lens
(d) Plane lens
Ans: (b) Converging lens
Q14. The SI unit of power of a lens is –
(a) Newton
(b) Hertz
(c) Dioptre
(d) Joule
Ans: (c) Dioptre
Q15. A concave lens always forms image which is –
(a) Real, inverted, larger
(b) Virtual, erect, diminished
(c) Real, erect, same size
(d) Virtual, inverted, larger
Ans: (b) Virtual, erect, diminished
Fill in the Blanks
- The straight-line path of light is called a ray of light.
- Image formed by a plane mirror is virtual and erect.
- The centre of a spherical mirror is called centre of curvature.
- The relation between radius of curvature (R) and focal length (f) is R = 2f.
- The midpoint of a mirror surface is called pole.
- Concave mirrors are used in dentist’s mirrors.
- Convex mirrors are used as rear-view mirrors in vehicles.
- The distance between the pole and focus is called focal length.
- The laws of reflection are valid for all types of mirrors.
- Refraction occurs due to change in speed of light.
- The law of refraction is also known as Snell’s law.
- A convex lens converges light rays, so it is called a converging lens.
- The power of a lens is the reciprocal of its focal length.
- One dioptre (1D) is the power of a lens of focal length 1 metre.
- A concave lens always gives a virtual and diminished image.
📝 True/False Questions
Light always travels in straight line in all conditions.
Ans: False (In diffraction it bends around edges).
The image formed by a plane mirror is virtual and erect.
Ans: True
