364691
When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is
1 \(130^{\circ}\)
2 \(120^{\circ}\)
3 \(110^{\circ}\)
4 \(140^{\circ}\)
Explanation:
The angle of deviation \((\delta)\) is \(\begin{aligned}& =180^{\circ}-(i+r)=180^{\circ}-2 r \\& =180^{\circ}-2 \times 30^{\circ}=180^{\circ}-60^{\circ}=120^{\circ}\end{aligned}\)
JEE - 2023
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364692
A person \(A B\) of height \(170\,cm\) is standing in front of a vertical plane mirror. His eyes are at height \(164\,cm\) from ground. At what distance from \(P\) should a hole be made in the mirror so that he cannot see the top of his head?
1 \(167\,cm\)
2 \(161\,cm\)
3 \(163\,cm\)
4 None of these
Explanation:
To see top of head, a ray should start from top of head and enter the eye as shown. If that point of incidence of mirror is punched, the head cannot be seen. From the ray diagram the hole has to be punched on mirror at \(3\;cm\) from top end.
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364693
A ray of light is incident on a plane mirror at an angle of \(60^\circ \) . The angle of deviation produced by the mirror is :
1 \(30^\circ \)
2 \(120^\circ \)
3 \(90^\circ \)
4 \(60^\circ \)
Explanation:
From geometery of figure, the angle of deviation produced by mirror \( = 30^\circ + 30^\circ = 60^\circ \)
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364694
A small object is placed \(10\;cm\) in front of a plane mirror. If you stand behind the object, \(30\;cm\) from the mirror and look at its image, for what distance must you focus your eyes?
1 \(40\;cm\)
2 \(80\;cm\)
3 \(20\;cm\)
4 \(60\;cm\)
Explanation:
Clearly, the distance of image from observer is \(40\;cm\).
364691
When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is
1 \(130^{\circ}\)
2 \(120^{\circ}\)
3 \(110^{\circ}\)
4 \(140^{\circ}\)
Explanation:
The angle of deviation \((\delta)\) is \(\begin{aligned}& =180^{\circ}-(i+r)=180^{\circ}-2 r \\& =180^{\circ}-2 \times 30^{\circ}=180^{\circ}-60^{\circ}=120^{\circ}\end{aligned}\)
JEE - 2023
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364692
A person \(A B\) of height \(170\,cm\) is standing in front of a vertical plane mirror. His eyes are at height \(164\,cm\) from ground. At what distance from \(P\) should a hole be made in the mirror so that he cannot see the top of his head?
1 \(167\,cm\)
2 \(161\,cm\)
3 \(163\,cm\)
4 None of these
Explanation:
To see top of head, a ray should start from top of head and enter the eye as shown. If that point of incidence of mirror is punched, the head cannot be seen. From the ray diagram the hole has to be punched on mirror at \(3\;cm\) from top end.
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364693
A ray of light is incident on a plane mirror at an angle of \(60^\circ \) . The angle of deviation produced by the mirror is :
1 \(30^\circ \)
2 \(120^\circ \)
3 \(90^\circ \)
4 \(60^\circ \)
Explanation:
From geometery of figure, the angle of deviation produced by mirror \( = 30^\circ + 30^\circ = 60^\circ \)
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364694
A small object is placed \(10\;cm\) in front of a plane mirror. If you stand behind the object, \(30\;cm\) from the mirror and look at its image, for what distance must you focus your eyes?
1 \(40\;cm\)
2 \(80\;cm\)
3 \(20\;cm\)
4 \(60\;cm\)
Explanation:
Clearly, the distance of image from observer is \(40\;cm\).
364691
When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is
1 \(130^{\circ}\)
2 \(120^{\circ}\)
3 \(110^{\circ}\)
4 \(140^{\circ}\)
Explanation:
The angle of deviation \((\delta)\) is \(\begin{aligned}& =180^{\circ}-(i+r)=180^{\circ}-2 r \\& =180^{\circ}-2 \times 30^{\circ}=180^{\circ}-60^{\circ}=120^{\circ}\end{aligned}\)
JEE - 2023
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364692
A person \(A B\) of height \(170\,cm\) is standing in front of a vertical plane mirror. His eyes are at height \(164\,cm\) from ground. At what distance from \(P\) should a hole be made in the mirror so that he cannot see the top of his head?
1 \(167\,cm\)
2 \(161\,cm\)
3 \(163\,cm\)
4 None of these
Explanation:
To see top of head, a ray should start from top of head and enter the eye as shown. If that point of incidence of mirror is punched, the head cannot be seen. From the ray diagram the hole has to be punched on mirror at \(3\;cm\) from top end.
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364693
A ray of light is incident on a plane mirror at an angle of \(60^\circ \) . The angle of deviation produced by the mirror is :
1 \(30^\circ \)
2 \(120^\circ \)
3 \(90^\circ \)
4 \(60^\circ \)
Explanation:
From geometery of figure, the angle of deviation produced by mirror \( = 30^\circ + 30^\circ = 60^\circ \)
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364694
A small object is placed \(10\;cm\) in front of a plane mirror. If you stand behind the object, \(30\;cm\) from the mirror and look at its image, for what distance must you focus your eyes?
1 \(40\;cm\)
2 \(80\;cm\)
3 \(20\;cm\)
4 \(60\;cm\)
Explanation:
Clearly, the distance of image from observer is \(40\;cm\).
364691
When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is
1 \(130^{\circ}\)
2 \(120^{\circ}\)
3 \(110^{\circ}\)
4 \(140^{\circ}\)
Explanation:
The angle of deviation \((\delta)\) is \(\begin{aligned}& =180^{\circ}-(i+r)=180^{\circ}-2 r \\& =180^{\circ}-2 \times 30^{\circ}=180^{\circ}-60^{\circ}=120^{\circ}\end{aligned}\)
JEE - 2023
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364692
A person \(A B\) of height \(170\,cm\) is standing in front of a vertical plane mirror. His eyes are at height \(164\,cm\) from ground. At what distance from \(P\) should a hole be made in the mirror so that he cannot see the top of his head?
1 \(167\,cm\)
2 \(161\,cm\)
3 \(163\,cm\)
4 None of these
Explanation:
To see top of head, a ray should start from top of head and enter the eye as shown. If that point of incidence of mirror is punched, the head cannot be seen. From the ray diagram the hole has to be punched on mirror at \(3\;cm\) from top end.
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364693
A ray of light is incident on a plane mirror at an angle of \(60^\circ \) . The angle of deviation produced by the mirror is :
1 \(30^\circ \)
2 \(120^\circ \)
3 \(90^\circ \)
4 \(60^\circ \)
Explanation:
From geometery of figure, the angle of deviation produced by mirror \( = 30^\circ + 30^\circ = 60^\circ \)
PHXII09:RAY OPTICS AND OPTICAL INSTRUMENTS
364694
A small object is placed \(10\;cm\) in front of a plane mirror. If you stand behind the object, \(30\;cm\) from the mirror and look at its image, for what distance must you focus your eyes?
1 \(40\;cm\)
2 \(80\;cm\)
3 \(20\;cm\)
4 \(60\;cm\)
Explanation:
Clearly, the distance of image from observer is \(40\;cm\).
