Question 1: A toy is placed at 10 cm in front of a plane mirror. What is the distance of image from the mirror?
Answer: (c) 10 cm
Question 2: A candle is 30 cm high. What is the height of its image in a plane mirror?
Answer: (c) 30 cm
Question 3: Which of the following works on the concept of multiple reflections?
Answer: (c) Kaleidoscope
Question 4: How many cells are there in a Braille character?
Answer: (d) 6
Question 5: Which of the following is a tactile aid?
Answer: (d) All of the above
Question 6: The human eye can clearly see up to which distance?
Answer: (a) Infinity
Question 7: The human eye cannot clearly see less than which distance?
Answer: (b) 25 cm
Question 8: Angle of incidence is 15°, then what is the angle of reflection?
Answer: (a) 15°
Question 9: Which of the following will produce a regular reflection?
Answer: (d) Mirror
Question 10: The colour of iris in a person is green. What is the colour of eye in that person?
Answer: (b) Green
Question 1: What is light?
Answer: Light is a form of energy. It helps in the sense of vision.
Question 2: What is reflection of light?
Answer: When light falls on a shiny surface, most of it bounces back. This phenomenon is called reflection of light.
Question 3: What is incident ray?
Answer: The ray of light falling on a reflecting surface is called incident ray.
Question 4: What is reflected ray?
Answer: The ray of light coming back from a reflecting surface is called reflected ray.
Question 5: What is normal?
Answer: The perpendicular on reflecting surface at the point of incidence is called normal.
Question 6: What is angle of incidence?
Answer: The angle between incident ray and normal is called angle of incidence.
Question 7: What is angle of reflection?
Answer: The angle between reflected ray and normal is called angle of reflection.
Question 8: What is the nature of image in plane mirror?
Answer: In a plane mirror, image is erect, virtual and of the same size as object, and is laterally inverted.
Question 9: What is persistence of vision?
Answer: An image stays on retina for 1/16 of a second. This is called persistence of vision.
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