Tuesday, March 31, 2020

1. Light – Reflection and Refraction

Multiple Choice Question :


Q1. Which of the following English letter shows lateral inversion?

H
O
I
L
Solution
The letter ‘L’ shows lateral inversion. Rest all appear same after reflection.  
Q2. In a lateral inversion
The left side of the object becomes the right side of the image and vice-versa.
The right side of the object remains the right side of the image.
The left side of the object remains the left side of the image.
None of the above
Solution
In a lateral inversion, the left side of the object becomes the right side of the image formed by the plane mirror and vice-versa.
Q3. A virtual image
can be projected on the screen.
cannot be projected on the screen.
may or may not be projected on the screen.
projected on the eyes only.
Solution
Virtual image cannot be obtained on the screen. It is seen only by looking into a mirror (or a lens).
Q4. Light always travels along a
Curved path
Circular path
Straight line path
Zigzag path
Solution
Light always travels in a straight line path.

Q5. Which of the following capital English letter does not show lateral inversion?
F
G
I
L
Solution
The letter I does not show lateral inversion. It appears the same after reflection.

Q6. An observer moves towards a stationary plane mirror at a speed of 4 m/s. The speed of image with respect to mirror is __________.
4 m/s towards the mirror
8 m/s towards the mirror
4 m/s away from the mirror
8 m/s away from the mirror
Solution
As the observer comes closer to the plane mirror, the image also comes closer. Also, in case of plane mirror, object distance = image distance. Hence, the speed of the image w.r.t. mirror is also 4 m/s which moves towards the mirror.
Q7. Through which medium does light propagate easily?
Translucent medium
Transparent medium
Opaque medium
Partially translucent medium
Solution
A medium through which light propagates easily is a transparent medium. For example air, water, glass etc.
Q8. The focal length of a plane mirror is ________ .
- 1
Zero
Infinity
+1
Solution
The focal length of a plane mirror is infinity as the image can be formed at an infinite distance inside the mirror.
Q9. Raj is standing in front of a plane mirror. The distance between Raj and his image is 100 cm. If the distance between the mirror and image is 'x' cm then what could be the possible value of x?
x = 50 cm
x = 100 cm
x = 200 cm
x = 25 cm
Solution
x = 50 cm For a plane, a mirror the distance between the object and the mirror is equal to the distance between the mirror and image. Thus, the distance between mirror and image is 50 cm. 



Q10. Angle of incidence is
the angle between the reflected ray and the normal.
the angle between the reflected ray and the mirror surface.
the angle between the incident ray and the normal.
the angle between the reflected ray and the incident ray.
Solution
Angle of incidence is the angle formed between the incident ray and the normal to the reflecting surface.  
Q11. Harry is standing in front of a plane mirror at a distance of 6 m. His image on the other side will form at a distance of
3 m
9 m
6 m
12 m
Solution
For reflection through a plane mirror, Image distance (v) = Object distance (u) = 6 m
Q12. Which among the following is true for a plane mirror?
Angle of incidence is always equal to angle of reflection.
Angle of incidence is not always equal to angle of reflection.
Angle of incidence is the angle between the reflected ray and the incident ray.
Angle of incidence is the angle between incident ray and the mirror surface.
Solution
According to the law of reflection, the angle of incidence is always equal to the angle of reflection. Also, an angle of incidence is the angle between the incident ray and the normal to the reflecting surface.
Q13. Which among the following is not true for a plane mirror?
Image formed is always erect.
Image is always formed at infinity.
Lateral inversion always takes place in a plane mirror.
Image formed by a plane mirror is always virtual
Solution
The image is formed by a plane mirror is always at the same distance behind the mirror as the object is in front of the mirror.
Q14. Angle of reflection is:
the angle between the reflected ray and the normal.
the angle between the reflected ray and the mirror surface.
the angle between the incident ray and the normal.
the angle between the reflected ray and the incident ray.
Solution
Angle of reflection is the angle formed between the reflected ray and the normal.
Q15. A virtual image is formed when 
light rays actually meet at a point.
light rays do not actually meet at a point, but appear to meet when produced backwards.
light rays converge.
light rays meet on the back side of the mirror.
Solution
Virtual image formswhen light rays coming from an object do not actually meet but appear to meet at a point when produced backwards after reflection from the plane mirror
Q16. Rahul is standing 35 cm in front of a plane mirror.  The mirror is moved 2 cm towards Rahul. What will be the distance between Rahul and his image?
74 cm
64 cm
66 cm
76 cm
Solution
When the mirror is moved 2 cm towards Rahul, distance between him and the mirror is 35 - 2 = 33 cm Distance of Rahul from mirror = 33 cm  Thus, Distance of image from mirror = 33 cm Distance between Raul and his image = 33 cm + 33 cm = 66 cm
Q17. The angle between an incident ray and the reflecting surface is 55°. What will be the total angle between the incident and reflected ray? 
60°
70°
55°
90°
Solution
70°
Q18. The image formed by plane mirror is
Real and erect
Real and inverted
Virtual and inverted
Virtual and erect
Solution
Image formed by a plane mirror is always virtual and erect.
Q19. What will be the angle of reflection if light rays fall normally on a reflecting surface?
- 180º
180º
90º
Solution
The angle of incidence is the angle between the incident ray and the normal. For light incident normally on the reflecting surface, the angle of incidence is zero. According to the law of reflection, the angle of incidence is always equal to the angle of reflection. Thus, the angle of reflection is also zero.
Q20. Real image
can be projected on the screen
cannot be projected on the screen
may or may not be projected on the screen
projected on the eyes only
Solution
Real image is an image that can always be projected on the screen.
Q21. Which of the following correctly represents the nature of an image formed by a plane mirror? 
Erect, virtual, diminished
Erect, virtual and magnified
Erect, real and diminished
Erect, virtual and of the same size
Solution
The image formed by a plane mirror is erect, virtual and of the same size as that of the object. 











No comments:

Post a Comment