282862
The magnifying power of an refracting type of astronomical telescope is ' \(m\) '. If focal length of the eyepiece is doubled, the magnifying power will become
1 \(\mathrm{m}\)
2 housefly will be seen reduced in image
3 intensity of image will be decreased
4 intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Explanation:
C: Magnifying power \((\mathrm{m})=\frac{\mathrm{f}_{\mathrm{o}}}{\mathrm{f}_{\mathrm{e}}}\)
So, if \(\mathrm{f}_{\mathrm{e}}\) is doubled then magnifying power will be \(\mathrm{m} / 2\) 975. While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that(a) housefly will be seen enlarged in image
(b.) housefly will be seen reduced in image
(c.) intensity of image will be decreased
(d.) intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Ans: c
Exp: C: When house fly sits on the objective lens, light intensity will be decreased at objective because housefly will stop the light to fall on objective. Hence, intensity of image is decreased.
MHT-CET 2020
Ray Optics
282863
An object is clearly seen through an astronomical telescope of length \(50 \mathrm{~cm}\). The focal lengths of its objective and eyepiece respectively, can be
1 \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\)
2 \(-45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
3 \(45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
4 \(5 \mathrm{~cm}\) and \(45 \mathrm{~cm}\)
Explanation:
A: In an astronomical telescope, objective and eye piece are made up of convex lens with positive focal length. In addition the astronomical telescopes objective has a big aperture and focal length. As a result, the objective and eyepiece focal length can be \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\) respectively.
MHT-CET 2020
Ray Optics
282864
A simple microscope is used to see the object first in blue light and then in red light. Due to change from blue to red light, what is the effect on its magnifying power?
1 Magnifying power increases
2 Magnifying power decreases
3 Magnifying power is independent of colour of light
4 Magnifying power remains constant
Explanation:
B: We know that,
Magnification of simple microscope \((m)=1+\frac{D}{f}\)
As focal length of red light is greater than that of blue light. Hence, magnification \((\mathrm{m})\) is decrease.
MHT-CET 2020
Ray Optics
282865
What is the magnifying power of a simple microscope of focal length \(5 \mathrm{~cm}\), if the image is formed at the distance of distinct vision?
1 4
2 6
3 5
4 7
Explanation:
B: Given, \(\mathrm{f}=5 \mathrm{~cm}\), We know that,
Magnifying power of simple microscope when image is formed at distance of distinct vision is -
\(\begin{aligned}
\mathrm{m}=1+\frac{\mathrm{D}}{\mathrm{f}} \\
\mathrm{m}=1+\frac{25}{5} \\
\mathrm{~m}=1+5 \\
\mathrm{~m}=6
\end{aligned}\)
282862
The magnifying power of an refracting type of astronomical telescope is ' \(m\) '. If focal length of the eyepiece is doubled, the magnifying power will become
1 \(\mathrm{m}\)
2 housefly will be seen reduced in image
3 intensity of image will be decreased
4 intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Explanation:
C: Magnifying power \((\mathrm{m})=\frac{\mathrm{f}_{\mathrm{o}}}{\mathrm{f}_{\mathrm{e}}}\)
So, if \(\mathrm{f}_{\mathrm{e}}\) is doubled then magnifying power will be \(\mathrm{m} / 2\) 975. While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that(a) housefly will be seen enlarged in image
(b.) housefly will be seen reduced in image
(c.) intensity of image will be decreased
(d.) intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Ans: c
Exp: C: When house fly sits on the objective lens, light intensity will be decreased at objective because housefly will stop the light to fall on objective. Hence, intensity of image is decreased.
MHT-CET 2020
Ray Optics
282863
An object is clearly seen through an astronomical telescope of length \(50 \mathrm{~cm}\). The focal lengths of its objective and eyepiece respectively, can be
1 \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\)
2 \(-45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
3 \(45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
4 \(5 \mathrm{~cm}\) and \(45 \mathrm{~cm}\)
Explanation:
A: In an astronomical telescope, objective and eye piece are made up of convex lens with positive focal length. In addition the astronomical telescopes objective has a big aperture and focal length. As a result, the objective and eyepiece focal length can be \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\) respectively.
MHT-CET 2020
Ray Optics
282864
A simple microscope is used to see the object first in blue light and then in red light. Due to change from blue to red light, what is the effect on its magnifying power?
1 Magnifying power increases
2 Magnifying power decreases
3 Magnifying power is independent of colour of light
4 Magnifying power remains constant
Explanation:
B: We know that,
Magnification of simple microscope \((m)=1+\frac{D}{f}\)
As focal length of red light is greater than that of blue light. Hence, magnification \((\mathrm{m})\) is decrease.
MHT-CET 2020
Ray Optics
282865
What is the magnifying power of a simple microscope of focal length \(5 \mathrm{~cm}\), if the image is formed at the distance of distinct vision?
1 4
2 6
3 5
4 7
Explanation:
B: Given, \(\mathrm{f}=5 \mathrm{~cm}\), We know that,
Magnifying power of simple microscope when image is formed at distance of distinct vision is -
\(\begin{aligned}
\mathrm{m}=1+\frac{\mathrm{D}}{\mathrm{f}} \\
\mathrm{m}=1+\frac{25}{5} \\
\mathrm{~m}=1+5 \\
\mathrm{~m}=6
\end{aligned}\)
282862
The magnifying power of an refracting type of astronomical telescope is ' \(m\) '. If focal length of the eyepiece is doubled, the magnifying power will become
1 \(\mathrm{m}\)
2 housefly will be seen reduced in image
3 intensity of image will be decreased
4 intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Explanation:
C: Magnifying power \((\mathrm{m})=\frac{\mathrm{f}_{\mathrm{o}}}{\mathrm{f}_{\mathrm{e}}}\)
So, if \(\mathrm{f}_{\mathrm{e}}\) is doubled then magnifying power will be \(\mathrm{m} / 2\) 975. While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that(a) housefly will be seen enlarged in image
(b.) housefly will be seen reduced in image
(c.) intensity of image will be decreased
(d.) intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Ans: c
Exp: C: When house fly sits on the objective lens, light intensity will be decreased at objective because housefly will stop the light to fall on objective. Hence, intensity of image is decreased.
MHT-CET 2020
Ray Optics
282863
An object is clearly seen through an astronomical telescope of length \(50 \mathrm{~cm}\). The focal lengths of its objective and eyepiece respectively, can be
1 \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\)
2 \(-45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
3 \(45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
4 \(5 \mathrm{~cm}\) and \(45 \mathrm{~cm}\)
Explanation:
A: In an astronomical telescope, objective and eye piece are made up of convex lens with positive focal length. In addition the astronomical telescopes objective has a big aperture and focal length. As a result, the objective and eyepiece focal length can be \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\) respectively.
MHT-CET 2020
Ray Optics
282864
A simple microscope is used to see the object first in blue light and then in red light. Due to change from blue to red light, what is the effect on its magnifying power?
1 Magnifying power increases
2 Magnifying power decreases
3 Magnifying power is independent of colour of light
4 Magnifying power remains constant
Explanation:
B: We know that,
Magnification of simple microscope \((m)=1+\frac{D}{f}\)
As focal length of red light is greater than that of blue light. Hence, magnification \((\mathrm{m})\) is decrease.
MHT-CET 2020
Ray Optics
282865
What is the magnifying power of a simple microscope of focal length \(5 \mathrm{~cm}\), if the image is formed at the distance of distinct vision?
1 4
2 6
3 5
4 7
Explanation:
B: Given, \(\mathrm{f}=5 \mathrm{~cm}\), We know that,
Magnifying power of simple microscope when image is formed at distance of distinct vision is -
\(\begin{aligned}
\mathrm{m}=1+\frac{\mathrm{D}}{\mathrm{f}} \\
\mathrm{m}=1+\frac{25}{5} \\
\mathrm{~m}=1+5 \\
\mathrm{~m}=6
\end{aligned}\)
282862
The magnifying power of an refracting type of astronomical telescope is ' \(m\) '. If focal length of the eyepiece is doubled, the magnifying power will become
1 \(\mathrm{m}\)
2 housefly will be seen reduced in image
3 intensity of image will be decreased
4 intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Explanation:
C: Magnifying power \((\mathrm{m})=\frac{\mathrm{f}_{\mathrm{o}}}{\mathrm{f}_{\mathrm{e}}}\)
So, if \(\mathrm{f}_{\mathrm{e}}\) is doubled then magnifying power will be \(\mathrm{m} / 2\) 975. While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that(a) housefly will be seen enlarged in image
(b.) housefly will be seen reduced in image
(c.) intensity of image will be decreased
(d.) intensity of image will be increased#[examname: AP EAMCET (Medical)-07.10.2020, Shift-I,Manipal UGET-2011]#
Ans: c
Exp: C: When house fly sits on the objective lens, light intensity will be decreased at objective because housefly will stop the light to fall on objective. Hence, intensity of image is decreased.
MHT-CET 2020
Ray Optics
282863
An object is clearly seen through an astronomical telescope of length \(50 \mathrm{~cm}\). The focal lengths of its objective and eyepiece respectively, can be
1 \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\)
2 \(-45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
3 \(45 \mathrm{~cm}\) and \(-5 \mathrm{~cm}\)
4 \(5 \mathrm{~cm}\) and \(45 \mathrm{~cm}\)
Explanation:
A: In an astronomical telescope, objective and eye piece are made up of convex lens with positive focal length. In addition the astronomical telescopes objective has a big aperture and focal length. As a result, the objective and eyepiece focal length can be \(45 \mathrm{~cm}\) and \(5 \mathrm{~cm}\) respectively.
MHT-CET 2020
Ray Optics
282864
A simple microscope is used to see the object first in blue light and then in red light. Due to change from blue to red light, what is the effect on its magnifying power?
1 Magnifying power increases
2 Magnifying power decreases
3 Magnifying power is independent of colour of light
4 Magnifying power remains constant
Explanation:
B: We know that,
Magnification of simple microscope \((m)=1+\frac{D}{f}\)
As focal length of red light is greater than that of blue light. Hence, magnification \((\mathrm{m})\) is decrease.
MHT-CET 2020
Ray Optics
282865
What is the magnifying power of a simple microscope of focal length \(5 \mathrm{~cm}\), if the image is formed at the distance of distinct vision?
1 4
2 6
3 5
4 7
Explanation:
B: Given, \(\mathrm{f}=5 \mathrm{~cm}\), We know that,
Magnifying power of simple microscope when image is formed at distance of distinct vision is -
\(\begin{aligned}
\mathrm{m}=1+\frac{\mathrm{D}}{\mathrm{f}} \\
\mathrm{m}=1+\frac{25}{5} \\
\mathrm{~m}=1+5 \\
\mathrm{~m}=6
\end{aligned}\)