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Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it?
Most Upvoted Answer
Two parallel plane mirrors A and B are placed at a separation 10cm . A...
At mirror B ∠i=∠r=450
At mirror A ∠i=∠r=450by geometry(alternate interior angle,considering both normal parallel lines)
Considering a triangle given in the figure.which is isosceles at mirror A
∠i+∠r=450+450=900 and other two are 450 each.
Let x=half of the base of triangle,and h=height of the triangle.
tan∠i=hx
tan450=10x;tan450=1
x=10cm
2x=2×10=20=length of base,it means this rays will get reflected from mirror A at a distance of 20 cm.
The total length of given mirror is 100 cm.So the no. of time rays will reflected from mirror A is 20100=5.
At mirror A ∠i=∠r=450by geometry(alternate interior angle,considering both normal parallel lines)
Considering a triangle given in the figure.which is isosceles at mirror A
∠i+∠r=450+450=900 and other two are 450 each.
Let x=half of the base of triangle,and h=height of the triangle.
tan∠i=hx
tan450=10x;tan450=1
x=10cm
2x=2×10=20=length of base,it means this rays will get reflected from mirror A at a distance of 20 cm.
The total length of given mirror is 100 cm.So the no. of time rays will reflected from mirror A is 20100=5.
Community Answer
Two parallel plane mirrors A and B are placed at a separation 10cm . A...
Given data:
Separation between the two parallel mirrors, AB = 10 cm
Length of the mirror, l = 100 cm
Angle of incidence, i = 45°
To find:
The number of times the incident ray is reflected from mirror A.
Solution:
When the incident ray falls on mirror B, it gets reflected according to the laws of reflection. The reflected ray then falls on mirror A and gets reflected again. This process continues until the ray goes out of the mirror system.
Let us assume that the incident ray falls on mirror B at point P. Let Q be the point where the reflected ray from mirror B meets mirror A. Let R be the point where the reflected ray from mirror A meets mirror B again. This process continues until the ray goes out of the mirror system.
Let us consider the path of the ray between points P and Q.
∠PBC = i (angle of incidence)
∠QCB = ∠PBC (alternate angles)
∠QCB = i
∠QBC = ∠BCP (alternate angles)
∠BCP = 90° (angle made by incident ray with mirror)
∠QBC = 90°
∠QBA = ∠QBC (alternate angles)
∠QBA = 90°
Therefore, the angle of incidence at point Q is 90°. Hence, the ray gets reflected back along the same path.
The path of the ray between points Q and R is the same as the path between points P and Q. Hence, the ray gets reflected back along the same path.
The path of the ray between points R and S is the same as the path between points P and Q. Hence, the ray gets reflected back along the same path.
This process continues until the ray goes out of the mirror system.
The total length of the path travelled by the ray between points P and Q is equal to the length of the mirror, l = 100 cm.
Hence, the ray gets reflected from mirror A 5 times before going out of the mirror system.
Therefore, the correct option is (B) 5.
Separation between the two parallel mirrors, AB = 10 cm
Length of the mirror, l = 100 cm
Angle of incidence, i = 45°
To find:
The number of times the incident ray is reflected from mirror A.
Solution:
When the incident ray falls on mirror B, it gets reflected according to the laws of reflection. The reflected ray then falls on mirror A and gets reflected again. This process continues until the ray goes out of the mirror system.
Let us assume that the incident ray falls on mirror B at point P. Let Q be the point where the reflected ray from mirror B meets mirror A. Let R be the point where the reflected ray from mirror A meets mirror B again. This process continues until the ray goes out of the mirror system.
Let us consider the path of the ray between points P and Q.
∠PBC = i (angle of incidence)
∠QCB = ∠PBC (alternate angles)
∠QCB = i
∠QBC = ∠BCP (alternate angles)
∠BCP = 90° (angle made by incident ray with mirror)
∠QBC = 90°
∠QBA = ∠QBC (alternate angles)
∠QBA = 90°
Therefore, the angle of incidence at point Q is 90°. Hence, the ray gets reflected back along the same path.
The path of the ray between points Q and R is the same as the path between points P and Q. Hence, the ray gets reflected back along the same path.
The path of the ray between points R and S is the same as the path between points P and Q. Hence, the ray gets reflected back along the same path.
This process continues until the ray goes out of the mirror system.
The total length of the path travelled by the ray between points P and Q is equal to the length of the mirror, l = 100 cm.
Hence, the ray gets reflected from mirror A 5 times before going out of the mirror system.
Therefore, the correct option is (B) 5.
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Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it?
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Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it?.
Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it?.
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Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it?, a detailed solution for Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? has been provided alongside types of Two parallel plane mirrors A and B are placed at a separation 10cm . A ray incident on the corner of mirror B at an angle of incidence 45 degree. Find the number of times this rays is reflected from mirror A if the mirror length of 100cm: (A) 4 (B) 5 (C) 6 (D) 7 Plz explain it? theory, EduRev gives you an
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