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7th Grade > Physics

LIGHT MCQs

Total Questions : 117 | Page 1 of 12 pages
Question 1. What are three characteristics of an image formed by plane mirrors?  [3 MARKS]
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Characteristics :3 Marks
Any 3:
The image formed by a plane mirror is:
1) Erect
2) Of the same size as of the object
3) Appears to be at the same distance from the mirror as the object is in front of it
4) Virtual
5) Laterally inverted
Question 2. Give three uses of Concave lens/mirrors.  [3 MARKS]
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Uses : 1 Mark each
(i) Amajor application of concave mirrors is in headlights of the car.
(ii) They are used in magnifying glasses and telescopes.
(iii)Shaving mirrors are another example that makes use of concave mirrors because of their curved and reflective surface.
Question 3. We can obtain an enlarged and erect image with a convex mirror.
  1.    True
  2.    False
  3.    Convex
  4.    Plano convex
 Discuss Question
Answer: Option B. -> False
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B
We cannot obtain an enlarged and erect image using a convex mirror. The image obtained with a convex mirror is virtual, upright and diminished in size.
Question 4. Convex mirror is also known as a divergent mirror.
  1.    True
  2.    False
  3.    Convex
  4.    Plano convex
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Answer: Option A. -> True
:
A
A convex mirror is a divergent mirror and a concave mirror is a convergent mirror.
Convex mirrors are called diverging mirrors because they diverge rays of light that hitthem and forma virtual image.
Concave mirrors arecalled converging mirrors because theybringincoming parallel rays together and causethese rays toconverge.
Question 5. A concave mirror always forms a virtual image.
  1.    True
  2.    False
  3.    Concave
  4.    Plano convex
 Discuss Question
Answer: Option B. -> False
:
B
A concave mirror does not always form a real image. In case, when an object is placed between the concave mirror and its focal length, it forms a virtual image which is erect and of larger size than the object as shown in the image.
A Concave Mirror Always Forms A Virtual Image.
Question 6. Light cannot bend around the corners by itself.
  1.    True
  2.    False
  3.    Concave
  4.    Plano convex
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Answer: Option A. -> True
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A
Light travels along a straight line. The fact that light travels in a straight path can be demonstrated by putting an object in its path. If the object is opaque and casts a dark shadow then, it shows that light travels in a straight line.
Question 7. The colours in a rainbow are labelled as:
  1.    VIBGYRO
  2.    VIBGYOR
  3.    VIBYORG
  4.    VIBYOGR
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Answer: Option B. -> VIBGYOR
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B
The colours in the rainboware labelled as VIBGYOR.
VIBGYOR stands for violet, indigo, blue, green, yellow, orange, and red.
Question 8. A virtual image can be formed on a screen.
  1.    True
  2.    False
  3.    Inner - convex; Outer - concave
  4.    Inner - convex; Outer - convex
 Discuss Question
Answer: Option B. -> False
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B
A virtual image cannot be formed on ascreen. Only real images are formed on a screen.
Question 9. A magnified virtual image can be produced by a  ______
  1.    plane mirror
  2.    concave mirror
  3.    convex mirror
  4.    prism
 Discuss Question
Answer: Option B. -> concave mirror
:
B
When the object is kept in between focus and the pole, a concave mirror forms an enlarged, virtual and erect image. A convex mirror always form diminished virtual image. A plane mirror always forms a virtual and erect image without any magnification.
Question 10. When and why is a rainbow formed?  [3 MARKS]
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When: 1 Mark
Why: 2 Marks
Rainbows happen when sunlight and rain combine in a very specific way.Indeed, rainbows often indicate that the rain has passed. Generally, it will be sunny when you see a rainbow, but rain clouds (usually cumulonimbus ) will be just a short distance away. In order to see a rainbow, you'll need two ingredients: sunlight and raindrops.
Just after rainfall, the air in the atmosphere is fairly moist with water droplets still clinging on to some dust particles. When light falls on these water droplets and vapours, it gets dispersed into its constituent seven colours. These seven colours are in the shape of an arc and are known as a Rainbow.
When And Why Is A Rainbow Formed?  [3 MARKS]

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