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PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364665 The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are
A. Real
B. Erect
C. Smaller in size than object
D. Laterally inverted
Choose the most appropriate answer from the options given below.

1 B and C only

2 A, C and D only

3 B and D only

4 A and D only

JEE - 2023

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364666 Figure shows a plane mirror into which a light ray is incident. If the incident light ray is turned by $10^{\circ}$ and the mirror by $20^{\circ},$ as shown, then the angle turned by the reflected ray is :
supporting img

1

50^{\circ}

clockwise

2

60^{\circ}

clockwise

3

40^{\circ}

clockwise

4

30^{\circ}

clockwise

Explanation:

Due to clockwise rotation of incident ray, reflected ray turns by $10^{\circ}$ anticlockwise. Due to $20^{\circ}$ clockwise rotation of the mirror, reflected ray turns by $40^{\circ}$ clockwise. Hence, net rotation is $30^{\circ}$ clockwise.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364667 A boy of height $1.5 m$ with his eye level at $1.4 m$ stands before a plane mirror of length $0.75 m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8 m$ . Then :

1 The boy will see his full image.

2 The boy cannot see his hair.

3 The boy cannot see his feet.

4 The boy cannot see neither his hair nor his feet.

Explanation:

supporting img
$Tan θ = \frac{a}{x} \Rightarrow x Tan θ = a$
$\Rightarrow x Tan θ = a$
from the diagram $\Rightarrow 2 a = 0.1 m$
Hence he cannot see image.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364668 A man is 160 $c m$ tall and his eyes are 15 $c m$ below the top of his head. In order to see his entire height, right from the top to head, he uses a plane mirror kept at a distance of 1 $m$ from him. The minimum length of the plane mirror
required is

1 120

c m

2 95

c m

3 80

c m

4 105

c m

Explanation:

To see the complete image of an object by a plane mirror.
Required size of mirror $= \frac{1}{2} \times$ size of object
$= \frac{1}{2} \times 160 = 80 c m$ .
So correct option is (3)

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364669 A plane mirror makes an angle of $30^{\circ}$ with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray

1

60^{\circ}

2

90^{\circ}

3

45^{\circ}

4

30^{\circ}

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364665 The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are
A. Real
B. Erect
C. Smaller in size than object
D. Laterally inverted
Choose the most appropriate answer from the options given below.

1 B and C only

2 A, C and D only

3 B and D only

4 A and D only

JEE - 2023

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364666 Figure shows a plane mirror into which a light ray is incident. If the incident light ray is turned by $10^{\circ}$ and the mirror by $20^{\circ},$ as shown, then the angle turned by the reflected ray is :
supporting img

1

50^{\circ}

clockwise

2

60^{\circ}

clockwise

3

40^{\circ}

clockwise

4

30^{\circ}

clockwise

Explanation:

Due to clockwise rotation of incident ray, reflected ray turns by $10^{\circ}$ anticlockwise. Due to $20^{\circ}$ clockwise rotation of the mirror, reflected ray turns by $40^{\circ}$ clockwise. Hence, net rotation is $30^{\circ}$ clockwise.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364667 A boy of height $1.5 m$ with his eye level at $1.4 m$ stands before a plane mirror of length $0.75 m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8 m$ . Then :

1 The boy will see his full image.

2 The boy cannot see his hair.

3 The boy cannot see his feet.

4 The boy cannot see neither his hair nor his feet.

Explanation:

supporting img
$Tan θ = \frac{a}{x} \Rightarrow x Tan θ = a$
$\Rightarrow x Tan θ = a$
from the diagram $\Rightarrow 2 a = 0.1 m$
Hence he cannot see image.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364668 A man is 160 $c m$ tall and his eyes are 15 $c m$ below the top of his head. In order to see his entire height, right from the top to head, he uses a plane mirror kept at a distance of 1 $m$ from him. The minimum length of the plane mirror
required is

1 120

c m

2 95

c m

3 80

c m

4 105

c m

Explanation:

To see the complete image of an object by a plane mirror.
Required size of mirror $= \frac{1}{2} \times$ size of object
$= \frac{1}{2} \times 160 = 80 c m$ .
So correct option is (3)

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364669 A plane mirror makes an angle of $30^{\circ}$ with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray

1

60^{\circ}

2

90^{\circ}

3

45^{\circ}

4

30^{\circ}

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364665 The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are
A. Real
B. Erect
C. Smaller in size than object
D. Laterally inverted
Choose the most appropriate answer from the options given below.

1 B and C only

2 A, C and D only

3 B and D only

4 A and D only

JEE - 2023

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364666 Figure shows a plane mirror into which a light ray is incident. If the incident light ray is turned by $10^{\circ}$ and the mirror by $20^{\circ},$ as shown, then the angle turned by the reflected ray is :
supporting img

1

50^{\circ}

clockwise

2

60^{\circ}

clockwise

3

40^{\circ}

clockwise

4

30^{\circ}

clockwise

Explanation:

Due to clockwise rotation of incident ray, reflected ray turns by $10^{\circ}$ anticlockwise. Due to $20^{\circ}$ clockwise rotation of the mirror, reflected ray turns by $40^{\circ}$ clockwise. Hence, net rotation is $30^{\circ}$ clockwise.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364667 A boy of height $1.5 m$ with his eye level at $1.4 m$ stands before a plane mirror of length $0.75 m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8 m$ . Then :

1 The boy will see his full image.

2 The boy cannot see his hair.

3 The boy cannot see his feet.

4 The boy cannot see neither his hair nor his feet.

Explanation:

supporting img
$Tan θ = \frac{a}{x} \Rightarrow x Tan θ = a$
$\Rightarrow x Tan θ = a$
from the diagram $\Rightarrow 2 a = 0.1 m$
Hence he cannot see image.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364668 A man is 160 $c m$ tall and his eyes are 15 $c m$ below the top of his head. In order to see his entire height, right from the top to head, he uses a plane mirror kept at a distance of 1 $m$ from him. The minimum length of the plane mirror
required is

1 120

c m

2 95

c m

3 80

c m

4 105

c m

Explanation:

To see the complete image of an object by a plane mirror.
Required size of mirror $= \frac{1}{2} \times$ size of object
$= \frac{1}{2} \times 160 = 80 c m$ .
So correct option is (3)

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364669 A plane mirror makes an angle of $30^{\circ}$ with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray

1

60^{\circ}

2

90^{\circ}

3

45^{\circ}

4

30^{\circ}

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364665 The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are
A. Real
B. Erect
C. Smaller in size than object
D. Laterally inverted
Choose the most appropriate answer from the options given below.

1 B and C only

2 A, C and D only

3 B and D only

4 A and D only

JEE - 2023

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364666 Figure shows a plane mirror into which a light ray is incident. If the incident light ray is turned by $10^{\circ}$ and the mirror by $20^{\circ},$ as shown, then the angle turned by the reflected ray is :
supporting img

1

50^{\circ}

clockwise

2

60^{\circ}

clockwise

3

40^{\circ}

clockwise

4

30^{\circ}

clockwise

Explanation:

Due to clockwise rotation of incident ray, reflected ray turns by $10^{\circ}$ anticlockwise. Due to $20^{\circ}$ clockwise rotation of the mirror, reflected ray turns by $40^{\circ}$ clockwise. Hence, net rotation is $30^{\circ}$ clockwise.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364667 A boy of height $1.5 m$ with his eye level at $1.4 m$ stands before a plane mirror of length $0.75 m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8 m$ . Then :

1 The boy will see his full image.

2 The boy cannot see his hair.

3 The boy cannot see his feet.

4 The boy cannot see neither his hair nor his feet.

Explanation:

supporting img
$Tan θ = \frac{a}{x} \Rightarrow x Tan θ = a$
$\Rightarrow x Tan θ = a$
from the diagram $\Rightarrow 2 a = 0.1 m$
Hence he cannot see image.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364668 A man is 160 $c m$ tall and his eyes are 15 $c m$ below the top of his head. In order to see his entire height, right from the top to head, he uses a plane mirror kept at a distance of 1 $m$ from him. The minimum length of the plane mirror
required is

1 120

c m

2 95

c m

3 80

c m

4 105

c m

Explanation:

To see the complete image of an object by a plane mirror.
Required size of mirror $= \frac{1}{2} \times$ size of object
$= \frac{1}{2} \times 160 = 80 c m$ .
So correct option is (3)

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364669 A plane mirror makes an angle of $30^{\circ}$ with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray

1

60^{\circ}

2

90^{\circ}

3

45^{\circ}

4

30^{\circ}

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364665 The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are
A. Real
B. Erect
C. Smaller in size than object
D. Laterally inverted
Choose the most appropriate answer from the options given below.

1 B and C only

2 A, C and D only

3 B and D only

4 A and D only

JEE - 2023

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364666 Figure shows a plane mirror into which a light ray is incident. If the incident light ray is turned by $10^{\circ}$ and the mirror by $20^{\circ},$ as shown, then the angle turned by the reflected ray is :
supporting img

1

50^{\circ}

clockwise

2

60^{\circ}

clockwise

3

40^{\circ}

clockwise

4

30^{\circ}

clockwise

Explanation:

Due to clockwise rotation of incident ray, reflected ray turns by $10^{\circ}$ anticlockwise. Due to $20^{\circ}$ clockwise rotation of the mirror, reflected ray turns by $40^{\circ}$ clockwise. Hence, net rotation is $30^{\circ}$ clockwise.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364667 A boy of height $1.5 m$ with his eye level at $1.4 m$ stands before a plane mirror of length $0.75 m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8 m$ . Then :

1 The boy will see his full image.

2 The boy cannot see his hair.

3 The boy cannot see his feet.

4 The boy cannot see neither his hair nor his feet.

Explanation:

supporting img
$Tan θ = \frac{a}{x} \Rightarrow x Tan θ = a$
$\Rightarrow x Tan θ = a$
from the diagram $\Rightarrow 2 a = 0.1 m$
Hence he cannot see image.

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364668 A man is 160 $c m$ tall and his eyes are 15 $c m$ below the top of his head. In order to see his entire height, right from the top to head, he uses a plane mirror kept at a distance of 1 $m$ from him. The minimum length of the plane mirror
required is

1 120

c m

2 95

c m

3 80

c m

4 105

c m

Explanation:

To see the complete image of an object by a plane mirror.
Required size of mirror $= \frac{1}{2} \times$ size of object
$= \frac{1}{2} \times 160 = 80 c m$ .
So correct option is (3)

PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS

364669 A plane mirror makes an angle of $30^{\circ}$ with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray

1

60^{\circ}

2

90^{\circ}

3

45^{\circ}

4

30^{\circ}