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Q9
(CDS-I/2015)
Science & Technology › Basic Science (Physics, Chemistry, Biology) › Geometrical optics
Answer Verified
A person standing 1 m in front of a plane mirror approaches the mirror by 40 cm. The new distance between the person and his image in the plane mirror is
Result
Your answer:
—
·
Correct:
B
Explanation
In a plane mirror, the distance of the image from the mirror is always equal to the distance of the object from the mirror. Initially, the person is standing 1 m (100 cm) in front of the mirror, meaning the image is 1 m behind it. When the person approaches the mirror by 40 cm, the new object distance becomes 100 cm - 40 cm = 60 cm. According to the principles of reflection in plane mirrors, the image will also be located 60 cm behind the mirror. The total distance between the person and his image is the sum of the object distance and the image distance (60 cm + 60 cm = 120 cm). Converting 120 cm back to meters gives 1.2 m. Therefore, the new separation between the person and his image is 1.2 m.
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