9. Light - Reflection and Refraction
рдЗрд╕ рдкреЗрдЬ рдкрд░ рдЖрдкрдХреЛ 9. Light - Reflection and Refraction рдХреЗ рд╕рднреА рдорд╣рддреНрд╡рдкреВрд░реНрдг рдмрд╣реБрд╡рд┐рдХрд▓реНрдкреАрдп рдкреНрд░рд╢реНрди (MCQ), рдкрд░реАрдХреНрд╖рд╛ рдЙрдкрдпреЛрдЧреА рдиреЛрдЯреНрд╕ рдФрд░ рдСрдирд▓рд╛рдЗрди рдХреНрд╡рд┐рдЬрд╝ рдорд┐рд▓реЗрдВрдЧреЗред рдЕрдкрдиреЗ рдЬреНрдЮрд╛рди рдХрд╛ рдкрд░реАрдХреНрд╖рдг рдХрд░рдиреЗ рдФрд░ рдмреЛрд░реНрдб/рдкреНрд░рддрд┐рдпреЛрдЧреА рдкрд░реАрдХреНрд╖рд╛ рдореЗрдВ рд╢рдд-рдкреНрд░рддрд┐рд╢рдд рдЕрдВрдХ рдкреНрд░рд╛рдкреНрдд рдХрд░рдиреЗ рдХреЗ рд▓рд┐рдП рдиреАрдЪреЗ рджрд┐рдП рдЧрдП рдореЙрдХ рдЯреЗрд╕реНрдЯ рдореЗрдВ рдЕрд╡рд╢реНрдп рднрд╛рдЧ рд▓реЗрдВред
ЁЯСЙ рдЕрдзреНрдпрд╛рдп рдХрд╛ рд╕рд╛рд░рд╛рдВрд╢ (Summary)
Dear students, in this chapter, we will deeply study 1 extremely fascinating, mysterious, and highly practical branch of physics known as 'Light - Reflection and Refraction'. Science is not just about merely cramming complex optical formulas or long definitions from closed books; rather, it is 1 highly wonderful art of practically understanding the miraculous events happening in the beautiful natural world around us from 1 strictly logical and scientific perspective. We are able to see this beautiful and colorful world entirely because of light. When light from 1 source strikes 1 object and safely bounces back to enter our eyes, that is exactly when we can see that specific object clearly.
Have you ever thought deeply about how, when you stand in front of 1 plain mirror in the morning to get ready, you perfectly see your exact 100 percent identical image? Or why does 1 straight pencil kept inside 1 transparent glass filled with water suddenly appear bent or broken at the surface? Why do the countless stars situated at an infinite distance in the dark night sky continuously twinkle? This is no magic trick at all, but all of these are 100 percent real-life examples of the wonderful natural phenomena of reflection and refraction of light. The bouncing back of light rays in the exact same medium after hitting 1 highly polished surface is called reflection, whereas the bending of light rays when they travel from 1 transparent medium into another transparent medium is called refraction.
From the strict perspective of the upcoming NCERT and RBSE board exams, this 9th chapter of science is highly scoring and extremely important for your 100 percent academic success. In the final board exams, not only direct theoretical questions are asked, but excellent analytical, numerical, and ray diagram-based long questions on mirrors and lenses definitely appear in the exact final paper every single year without fail. In this highly exciting learning journey, we will 1st logically understand the fundamental rules of spherical mirrors, specifically concave and convex mirrors. We will perfectly learn how to accurately draw 1 ray diagram by hand so you can easily predict the exact nature and size of 1 image formed by these mirrors. We will also scientifically understand why 1 convex mirror is always used as a rear-view mirror in vehicles to see the traffic behind.
Moving 1 little further in the chapter, we will logically analyze the complex but fascinating world of refraction. We will systematically study the refraction of light through 1 rectangular glass slab and deeply understand Snell's Law. The refractive index is 1 extremely crucial topic that mathematically tells us how much the speed of light perfectly decreases in 1 specific medium. After this, we will deeply study the exact working of spherical lenses, which include both convex and concave lenses. If 1 student cannot see the blackboard clearly, these specific lenses are used in their spectacles to correct their vision 100 percent accurately. Finally, we will completely study the power of 1 lens, which is strictly measured in Diopters.
To perfectly ensure your excellent and 100 percent strong board preparation, we have meticulously prepared highly accurate, high-level, and extremely exam-useful objective questions (MCQs) from all these complex topics. By continuously practicing again and again, you will surely learn critical time management and massively increase your speed of solving complex numerical questions in the final exam without making even 1 single mistake.
Feature: This is a 3-Level based unique quiz. To unlock the next level (Level 2 and 3), students must score at least 70% in the current level, making their board exam preparation 100% strong.
рдорд╣рддреНрд╡рдкреВрд░реНрдг рдкреНрд░рд╢реНрди (Important Questions)
PDF рдбрд╛рдЙрдирд▓реЛрдб рдХрд░реЗрдВрдЕрдзреНрдпрд╛рдп рдХреЗ рд╕рднреА рдкреНрд░рд╢реНрди (Revision Notes)
*рдиреЛрдЯ: рдпрд╣ рд╕реЗрдХреНрд╢рди рд░рд┐рд╡реАрдЬрди рдХреЗ рд▓рд┐рдП рд╣реИред рдЕрдкрдирд╛ рдЬреНрдЮрд╛рди рдкрд░рдЦрдиреЗ рдХреЗ рд▓рд┐рдП рдКрдкрд░ рджрд┐рдП рдЧрдП рдХреНрд╡рд┐рдЬрд╝ рдореЗрдВ рднрд╛рдЧ рд▓реЗрдВред
-
Light travels in a:
A) Curved line | B) Straight line | C) Any direction | D) None of these -
The center of the reflecting surface of a mirror is called the:
A) Pole | B) Center of curvature | C) Principal axis | D) Focus -
What is the relationship between radius of curvature (R) and focal length (f) of a spherical mirror?
A) f = R | B) f = R/2 | C) f = 2R | D) R = f/2 -
The image formed by a plane mirror is always:
A) Real | B) Virtual and erect | C) Inverted | D) Small -
Which mirror is used as a rear-view mirror in vehicles?
A) Concave mirror | B) Convex mirror | C) Plane mirror | D) Lens -
Which mirror is used for shaving?
A) Convex | B) Concave mirror | C) Plane | D) None of these -
What is the SI unit of Power of a lens?
A) Meter | B) Dioptre | C) Watt | D) Joule -
What is the speed of light in vacuum?
A) 3 x 10^8 m/s | B) 2 x 10^8 m/s | C) 3 x 10^5 m/s | D) 1 x 10^8 m/s -
How many laws of reflection of light are there?
A) One | B) Two | C) Three | D) Four -
Which mirror has the widest field of view?
A) Concave | B) Convex mirror | C) Plane | D) None of these -
The refractive index of glass compared to air is:
A) Less | B) More | C) Same | D) Zero -
A convex lens is also called a:
A) Diverging lens | B) Converging lens | C) Cylindrical lens | D) None of these -
A concave lens is also called a:
A) Converging lens | B) Diverging lens | C) Bifocal lens | D) None of these -
Which is the Mirror formula?
A) 1/v - 1/u = 1/f | B) 1/v + 1/u = 1/f | C) v + u = f | D) None of these -
Which is the Lens formula?
A) 1/v + 1/u = 1/f | B) 1/v - 1/u = 1/f | C) u - v = f | D) None of these -
Snell's law is related to:
A) Reflection | B) Refraction | C) Dispersion | D) None of these -
A real image is always:
A) Erect | B) Inverted | C) Small | D) Large -
A virtual image is always:
A) Inverted | B) Erect | C) Real | D) None of these -
Power of a lens P is equal to:
A) f | B) 1/f (f in meters) | C) v/u | D) m -
The change in direction of light when it passes from one transparent medium to another is:
A) Reflection | B) Refraction | C) Shadow | D) None of these -
When light enters from a rarer to a denser medium, it bends:
A) Away from the normal | B) Towards the normal | C) Goes straight | D) Bends backwards -
What is the refractive index of diamond?
A) 1.33 | B) 2.42 | C) 1.50 | D) 1.00 -
If the magnification (m) of an image is negative (-), the image will be:
A) Virtual | B) Real and inverted | C) Erect | D) Small -
The effective diameter of the circular outline of a spherical lens is called its:
A) Pole | B) Aperture | C) Focus | D) Radius -
What is the focal length of a plane mirror?
A) Zero | B) Infinite | C) 25 cm | D) 100 cm -
When an object is placed at the center of curvature (C) of a concave mirror, where will the image form?
A) At F | B) At C | C) At infinity | D) Beyond C -
Why does a coin placed in a bucket of water appear raised?
A) Due to reflection | B) Due to refraction | C) Total internal reflection | D) None of these -
The formula for magnification (m) produced by a lens is:
A) -v/u | B) v/u | C) f/u | D) 1/v -
The formula for magnification (m) produced by a mirror is:
A) v/u | B) -v/u | C) u/v | D) f -
The focal length of a convex mirror is 20 cm, its radius of curvature will be:
A) 10 cm | B) 40 cm | C) 20 cm | D) 5 cm -
The twinkling of stars is a result of:
A) Reflection | B) Atmospheric refraction | C) Dispersion | D) Scattering -
If the power of a lens is +2.0 D, its focal length will be:
A) -50 cm | B) +50 cm | C) 20 cm | D) 10 cm -
Where should an object be placed in front of a concave mirror to get a virtual and enlarged image?
A) At C | B) Between P and F | C) At infinity | D) At F -
The shift of a light ray from its original path while passing through a glass slab is called:
A) Reflection | B) Lateral displacement | C) Refraction | D) None of these -
The refractive index of a medium (n) is equal to:
A) v/c | B) c/v (Speed in air / Speed in medium) | C) c+v | D) c-v -
What is used as a reflector in torches and searchlights?
A) Convex mirror | B) Concave mirror | C) Plane mirror | D) Lens -
The refractive index of water with respect to air is:
A) 1.50 | B) 1.33 | C) 2.42 | D) 1.00 -
In which condition does refraction of light not occur?
A) When falling obliquely | B) When falling along the normal (at 90┬░) | C) At any angle | D) None of these -
The central point of a lens through which light passes without bending:
A) Pole | B) Optical centre | C) Focus | D) Centre -
A spherical mirror whose reflecting surface is curved outwards:
A) Concave | B) Convex | C) Plane | D) None of these -
Where will the image form if an object is placed at '2F1' in front of a convex lens?
A) At F2 | B) At 2F2 | C) At infinity | D) Between F1 and O -
The image formed by a concave lens is always:
A) Real and large | B) Virtual, erect and diminished | C) Real and small | D) Virtual and large -
According to the New Cartesian Sign Convention, the focal length of a convex mirror is:
A) Negative | B) Positive | C) Zero | D) None of these -
A ray of light enters from air to oil (n=1.45). What will be the speed of light in oil?
A) 3 x 10^8 m/s | B) 2.07 x 10^8 m/s | C) 1.5 x 10^8 m/s | D) None of these -
What is used to concentrate sunlight in solar furnaces?
A) Large convex mirrors | B) Large concave mirrors | C) Plane mirrors | D) None of these -
The focal length (f) of a concave mirror is always taken as:
A) Positive | B) Negative | C) Zero | D) None of these -
Which lens would you prefer to use while reading small letters found in a dictionary?
A) Concave lens of f=50 cm | B) Convex lens of f=5 cm | C) Concave lens of f=5 cm | D) Convex lens of f=50 cm -
Magnification m = h'/h. If h' = h, the size of the image is ________ to the object:
A) Larger | B) Equal | C) Smaller | D) None of these -
The phenomenon occurring due to change in 'velocity' when light enters from one transparent medium to another:
A) Reflection | B) Refraction | C) Polarization | D) None of these -
How will the graph between power and focal length of a lens look?
A) Straight line | B) Hyperbola | C) Circle | D) None of these -
A pencil partially immersed in water appears to be bent because:
A) Water is cold | B) Refraction occurs at the interface | C) Pencil breaks | D) None of these -
The angle between the normal and the incident ray is called:
A) Angle of reflection | B) Angle of incidence | C) Angle of refraction | D) Critical angle -
When does the formula P = P1 + P2 + ... apply?
A) When lenses are far apart | B) When lenses are in contact | C) Only for concave lenses | D) None of these -
When light travels from a denser to a rarer medium:
A) Speed decreases | B) Speed increases and it bends away from the normal | C) Speed remains same | D) None of these -
The principal axis of a spherical mirror is ________ to its pole:
A) Parallel | B) Normal | C) Oblique | D) None of these -
The laws of reflection apply to:
A) Only plane mirrors | B) Only concave mirrors | C) All reflecting surfaces | D) Only lenses -
Where does a concave mirror form the image of an object at infinity?
A) At C | B) At F | C) At P | D) Beyond C -
Magnification m = +1.5 means the image is ________ than the object:
A) Smaller | B) Enlarged and virtual | C) Inverted | D) Real -
The refractive index of glass is 1.5. The velocity of light in glass will be:
A) 3 x 10^8 m/s | B) 2 x 10^8 m/s | C) 2.25 x 10^8 m/s | D) 1.5 x 10^8 m/s -
The angle of reflection (r) is always equal to:
A) Angle of refraction | B) Angle of incidence (i) | C) Zero | D) 90┬░
0
0
0%
рдЕрдкрдирд╛ рд╕реБрдЭрд╛рд╡ рджреЗрдВ (Feedback)
рд╡реЗрдмрд╕рд╛рдЗрдЯ рдХреЛ рдФрд░ рдмреЗрд╣рддрд░ рдмрдирд╛рдиреЗ рдХреЗ рд▓рд┐рдП рдЕрдкрдиреЗ рд╡рд┐рдЪрд╛рд░ рд╣рдореЗрдВ рднреЗрдЬреЗрдВред