Light Mirrors and Lenses Class 8 MCQ
hardLight Mirrors and Lenses Class 8 MCQ
Light Mirrors and Lenses Class 8 MCQ
Question 1.
Which type of mirror is commonly used as a side-view mirror in vehicles?
(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Flat glass
Answer:
(c) Convex mirror
Question 2.
What happens to the image of an object when viewed in a concave mirror as the object moves closer?
(a) The image becomes larger and inverted
(b) The image remains the same size
(c) The image becomes smaller and erect
(d) The image disappears
Answer:
(a) The image becomes larger and inverted
Question 3.
According to the laws of reflection, what is the relationship between the angle of incidence and the angle of reflection?
(a) They are always equal
(b) The angle of incidence is always greater
(c) The angle of reflection is always greater
(d) They are unrelated
Answer:
(a) They are always equal
Question 4.
What type of lens is a magnifying glass?
(a) Concave lens
(b) Convex lens
(c) Plane lens
(d) Cylindrical lens
Answer:
(b) Convex lens
Question 5.
When light rays converge after reflecting off a concave mirror, which type of image is formed?
(a) A virtual image
(b) A real image
(c) No image
(d) A distorted image
Answer:
(b) A real image
Question 6.
In a convex mirror, how does the size of the image compare to the actual object?
(a) The image is larger
(b) The image is smaller
(c) The image is of the same size
(d) The image is inverted
Answer:
(b) The image is smaller
Question 7.
What is the primary use of convex mirrors in retail stores?
(a) To magnify products
(b) To provide a wide field of view for surveillance
(c) To create decorative effects
(d) To focus light on products
Answer:
(b) To provide a wide field of view for surveillance
Question 8.
When light strikes a plane mirror at an angle of incidence of 30^{\circ}, what is the angle between reflected ray and the mirror?
(a) 30°
(b) 60°
(c) 90°
(d) 0°
Answer:
(b) 60°
Question 9.
What occurs when you hold a concave mirror in sunlight and focus the light on a piece of paper?
(a) The paper gets cooler
(b) The paper ignites and burns
(c) The paper remains unchanged
(d) The paper reflects the light back
Answer:
(b) The paper ignites and burns
Question 10.
Which of the following statements is true regarding the image formed by a plane mirror?
(a) The image is always inverted
(b) The image is always larger than the object
(c) The image is always the same size as the object and erect
(d) The image cannot be seen
Answer:
(c) The image is always the same size as the object and erect.
Case Study
I. Convex mirrors for road safety
Convex mirrors play a vital role in enhancing road safety. Installed at intersections and sharp bends, they provide drivers with a wider field of view, allowing them to see oncoming traffic from different angles. The erect and diminished images formed by convex mirrors help prevent collisions by alerting drivers to potential hazards, showcasing their importance in traffic management and safety.
Question 1.
Why are convex mirrors commonly used at road intersections and sharp bends?
(a) They magnify the image of vehicles
(b) They provide a wider field of view
(c) They form inverted images
(d) They absorb light from headlights
Answer:
(b) They provide a wider field of view
Question 2.
What type of image is formed by a convex mirror?
(a) Real and enlarged
(b) Virtual and enlarged
(c) Real and diminished
(d) Virtual and diminished
Answer:
(d) Virtual and diminished
Question 3.
Convex mirrors are installed at ............ and sharp bends to improve visibility.
Answer:
intersections
Question 4.
The images formed by convex mirrors are ............ and ............ .
Answer:
erect, diminished
Question 5.
Convex mirrors form real and enlarged images, making them ideal for road safety. (True/False)
Answer:
False
II. Solar concentrators using concave mirrors
Concave mirrors are also utilised in solar concentrators, devices designed to focus sunlight onto a small area. By directing sunlight onto a sheet of paper, one can observe the intense heat generated at the focal point, which can even ignite the paper. This principle is harnessed in various solar energy applications, highlighting the innovative use of concave mirrors in renewable energy technologies.
Question 1.
What is the main function of a concave mirror in a solar concentrator?
(a) To scatter sunlight in all directions
(b) To absorb sunlight completely
(c) To focus sunlight onto a small area
(d) To reflect sunlight away from the device
Answer:
(c) To focus sunlight onto a small area
Question 2.
What happens when sunlight is focused by a concave mirror onto a sheet of paper?
(a) The paper becomes cold
(b) The paper glows in the dark
(c) The paper may ignite due to heat
(d) The paper reflects the sunlight
Answer:
(c) The paper may ignite due to heat
Question 3.
Concave mirrors are used in ............ to concentrate solar energy.
Answer:
solar concentrators
Question 4.
The point where sunlight is focused by a concave mirror is called the .............
Answer:
focal point
Question 5.
Concave mirrors scatter sunlight evenly, making them unsuitable for solar energy applications. (True/False)
Answer:
False