Welcome to this page on Numericals on Light for Class 10 Science chapter 10. These questions will help you improve your ranks with the great collection of Numericals on Light Class 10 of 3 marks questions. These light reflection and refraction class 10 questions and answers are from various topics and formulas like
Answer 1. This occurs due to the, phenomenon of refraction of light. Here, the ray of light from the coin travels from a denser medium to a rarer medium . In this process it bends away from the normal . The point from which the refracted rays appear to come gives the apparent position of the coin. As the rays appear to come from a point above the coin, so, the coin seems to be raised.
Solved Numericals On Light Reflection And Refraction For Class 10 Pdf Download
Download File 🔥 https://fancli.com/2y3YOu 🔥
Answer 3.
(1) New Cartesian sign conventions for measuring the various distances in the ray diagrams (reflection by spherical mirrors)
1. All the distances in a ray diagram are measured from the pole of the spherical mirror.
2. The distances measured in the direction of incident light are taken as positive.
3. The distances measured in the direction opposite to the direction of incident light are taken as negative.
4. The heights measured upwards and perpendiculars to the principal axis of the mirror are taken as positive.
5. The heights measured downwards and perpendiculars to the principal axis of the mirror are taken as negative.
Answer 3.
(2) Visit page -reflection-and-refraction.php#spherical-mirrors
We know that light is a form of energy and can undergo various phenomena like diffraction, reflection, refraction, interference, and polarisation. Refraction is the phenomenon that takes place due to the bending of light when it travels from medium to another. In this article, let us briefly understand the process of refraction.
Refraction of light is one of the most commonly observed phenomena, but other waves like sound waves and water waves also experience refraction. Refraction makes it possible for us to have optical instruments such as magnifying glasses, lenses and prisms. It is also because of the refraction of light that we are able to focus light on our retina.
Did you know that the twinkling effect of stars is due to atmospheric refraction? The starlight undergoes several refractions while reaching the Earth. This atmospheric refraction occurs in a medium of gradually changing refractive index.
1. Light travelling in air enters into an optical fibre of refractive index 1.44.
a) In which direction does the light bend?
b) If the angle of incidence on one end of the fibre is 22o, then what is the angle of refraction?
2. The light travelling through the optical fibre reaches the end of the optical fibre and exits into the air. If the angle of incidence at the end of the tube is 30o. Then what would the angle of refraction outside the fibre be?
Question 3.
State the two laws of reflection of light. (Delhi 2011)
Answer:
Laws of reflection of light states that
(i) The angle of incidence is equal to the angle of reflection.
(ii) The incident ray, the reflected ray and the normal to the mirror at the point of incidence all lie in the same plane.
Question 6.
Draw a labelled ray diagram to show the path of the reflected ray corresponding to an incident ray of light parallel to the principal axis of a convex mirror. Mark the angle of incidence and angle of reflection on it. (AI 2019)
Answer:
Question 10.
A ray of light is incident on a convex mirror as shown. Redraw the diagram and complete the path of this ray after reflection from the mirror. Mark angle of incidence and angle of reflection on it. (Delhi 2016)
Answer:
Question 19.
Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray of light parallel to the principal axis of a concave mirror. Mark the angle of incidence and angle of reflection on it. (Delhi 2014)
Answer:
Question 25.
Draw ray diagrams for the following cases when a ray of light:
(i) passing through centre of curvature of a concave mirror is incident on it.
(ii) parallel to principal axis is incident on convex mirror.
(iii) is passing through focus of a concave mirror incident on it. (2020)
Answer:
(i) Ray of light passing through centre of curvature of concave mirror, after reflection
(ii) Ray of light parallel to the principal axis is incident on a convex mirror after reflection appear to diverge from the principal focus of a convex mirror.
(iii) Ray of light passing through focus of a concave mirror after reflection will emerge parallel
Question 30.
Draw the following diagram in which a ray of light is incident on a concave/convex mirror, on your answer sheet. Show the path of this ray, after reflection, in each case.
Answer:
The path of the rays are shown in figure.
Question 34.
To construct a ray diagram we use two rays of light which are so chosen that it is easy to determine their directions after reflection from the mirror. Choose these two rays and state the path of these rays after reflection from a concave mirror. Use these two rays to find the nature and position of the image of an object placed at a distance of 15 cm from a concave mirror of focal length 10 cm. (Delhi 2015, AI 2012)
Answer:
We use two rays of light, one passing through the centre of curvature of a concave mirror, and another is parallel to the principal axis. After reflection, the ray passing through the centre of a concave mirror is reflected back along the same path and the ray parallel to the principal axis will pass through the principal focus.
u = -15 cm, f= -10 cm
From ray diagram, v = -30 cm, i.e., beyond C Nature of image is real, inverted and magnified.
Question 45.
To construct ray diagram we use two light rays which are so chosen that it is easy to know their directions after reflection from the mirror. List these two rays and state the path of these rays after reflection. Use these rays to locate the image of an object placed between centre of curvature and focus of a concave mirror. (AI2012)
Answer:
A ray parallel to the principal axis, after reflection, will pass through the principal focus in case of a concave mirror or appear to diverge from the principal focus in case of a convex mirror.
A ray passing through the centre of a curvature of a concave mirror or directed in the direction of the centre of curvature of a convex mirror, after reflection, is reflected back along the same path. The light rays come back along the same path because the incident rays fall on the mirror along the normal to the reflecting surface.
Question 52.
(a) To construct a ray diagram we use two rays which are so chosen that it is easy to know their directions after reflection from the mirror. Use these two rays and draw ray diagram to locate the image of an object placed between pole and focus of a concave mirror.
(b) A concave mirror produces three times magnified image on a screen. If the objects placed 20 cm in front of the mirror, how far is the screen from the object? (Delhi 2017)
Answer:
(a) Two lights rays whose path of reflection are priorly known are :
(i) When the incident ray passes through the centre of curvature of a concave mirror, it gets reflected in the same path.
(ii) When the ray is incident obliquely to the principal axis, towards the pole of mirror, it gets reflected back by making equal angles with the principal axis (laws of reflections).
Question 103.
(a) State the laws of refraction of light. Explain the term absolute refractive index of a medium and write an expression to relate it with the speed of light in vacuum.
(b) The absolute refractive indices of two media A and B are 2.0 and 1.5 respectively. If the speed of light in medium B is 2 108 m/s, calculate the speed of light in
(i) vacuum
(ii) medium A (Delhi 2015)
Answer:
(a) Refer to answer 74.
(b) Given that nA = 2.0, nA = 1.5, vA = 2 108 m/s
Question 107.
(a) Explain the following terms related to spherical lenses:
(i) optical centre
(ii) centres of curvature
(iii) principal axis (iv) aperture
(v) principal focus (vi) focal length
(b) A converging lens has focal length of 12 cm. Calculate at what distance should the object be placed from the lens so that it forms an image at 48 cm on the other side of the lens. (AI 2014)
Answer:
(a) (i) Optical centre : The centre point of a lens is known as the optical centre. It always lies inside the lens. A light beam passing through the optical centre without any deviation.
(ii) Centre of curvature : It is defined as the centre of the sphere of which the lens is originally a part of. Because the spherical lens consists of two spherical surfaces, the lens has two centre of curvature.
(iii) Principal axis : A straight line passing through the optical centre and principal focus of a spherical lens. This line is called the principal axis.
(iv) Aperture : The diameter of the reflecting surface of spherical lens is called its aperture.
(v) Principal focus : A number of rays parallel to the principal axis are falling on a lens.
These rays, after refraction from the lens, are appearing to converge to or diverge from a point on the principal axis. This point on the principal axis is called the principal focus of the lens.
(vi) Focal length: The distance between the optical centre and the principal focus of a spherical lens is called the focal length. It is represented by the letter f.
Question 110.
(a) State the laws of refraction of light. Give an expression to relate the absolute refractive index of a medium with speed of light in vacuum.
(b) The refractive indices of water and glass with respect to air are 4/3 and 3/2 respectively. If the speed of light in glass is 2 108 m s-1, find the speed of light in (i) air, (ii) water. (Delhi 2013)
Answer:
(a) Refer to answer 74.
(b) Refer to answer 66. 2351a5e196
download jungle marble blast 3 mod apk