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CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Optical instrument
Asked by tannudahiya80536
20th December 2022,
1:13 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
derive the expression for the magnifying Power and the length of a compound microscope using two convex lenses.
Asked by kamleshstarone392
16th April 2022,
6:26 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
derive an expression for the magnifying power of an astronomical telescope in normal adjustment?
Asked by shijurlytepz
12th October 2021,
6:56 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Define and write expression for magnifying power of an astronomical telescope in normal adjustment (i,e, when the final image is formed at infinity)
Asked by khanhill543
31st December 2020,
12:20 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Find the maximum magnifying power of a compound microscope having a 25 diopter lens as the objective, a 5 diopter lens as the eyepiece and the separation 30 cm between the two lenses. The least distance for clear vision is 25 cm.
Asked by ABHILASHA
15th September 2020,
6:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
the magniuifying power of a telescope is 9. when it adjusted for parallel rays the didtance b/w the eye piece and objective lens is 20cm find the focal length of both lenses
Asked by akgujrati04
22nd August 2020,
7:06 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
which mirror does used in microscope and why?
Asked by mazhartahsildar143
2nd May 2020,
1:32 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Is combination of a mirror and lens in syllabus of class 12?
Asked by govtsecschoolnayaganv051
24th February 2020,
4:17 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Derivation of compound microscope
Asked by phenomenal1ajisback
20th February 2020,
8:08 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
astronomical telesccope with full explaination
Asked by singhalakash8958
3rd March 2019,
10:11 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
A compound microscope consists of an objective of focal length 1 cm and eye piece of focal length 5 c separated by 12.2 cm. At what distance from the objective should an object be placed so that the final image is formed at least distance of distinct vision?
Asked by vishakhachandan026
23rd February 2019,
6:15 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
A convex lens of focal length 15 cm is placed in front of a convex mirror. Both are coaxial and the lens is 5 cm from the apex of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens ,it is found that the image coincides with the object. Calculate the radius of curvature of the mirror.
Asked by mridulabarua05
9th February 2019,
1:08 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
discuss about the qualitative Idea resolving power of astronomical telescope
Asked by ap996969
23rd January 2019,
6:01 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Q no 9
Asked by Varsneya Srinivas
24th December 2017,
11:43 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
What is a cassegrain telescope?
Asked by pksunilnair
4th December 2017,
9:46 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Please help me to solve this?
Please help me to solve this?
Asked by rajuharan
26th January 2017,
7:04 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
hello teachers well this question is not related to my course m student and passionately want a cosmos telesope should you just asking should give me a telesope if i top in my board exams i promise i say eveyone one that i leared from topperlearning
i just ask its your wish teachers if you dont give me than just tell me how it made but cosmos related not ordinary i just request as a student
Asked by saggugurupal
18th August 2016,
10:44 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
EXPLAIN DOPPLER EFFECT OF LIGHT.<I'VE STUDIED ABOUT RED SHIFT ,I HAVE NOT UNDERSTOOD IT>PLEASE EXPLAIN SO THAT I HAVE NO CONFUSION LEFT.
Asked by preethambasilmartis
22nd June 2016,
11:26 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
An angular magnification of30X is desired using objectve of focal length1.25 cm and an eye peice of focal length 5 cm. How would you set up compound icroscope
Asked by yashjha23
8th January 2016,
1:12 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
how power and length of aperture of lens is recquired in compound microscope and telescope
Asked by singhdivyanshu633
24th December 2015,
9:00 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
draw a ray diagram to show the image formation a compund microscope .explain briefly the working .derive an expression for its magnifying power.why the diameter of objective of microscope should be small?
Asked by mahamood.iphone
22nd December 2015,
12:13 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
define resolving power of compound microscope .how does the resolving power of a compound change when-a refractive index of medium between the object and objective lens increases b wavelength of the light used is increased c decreasing the diameter of objective d increasing the focal length of its objective
Asked by mahamood.iphone
21st December 2015,
10:34 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
define the resolving power of astronomical telescope.write the expression for it and state on what factors it depends
Asked by mahamood.iphone
21st December 2015,
10:27 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
can you please suggest me mnimum magnification required to build a astronomical telescope? how do size of aperture play role in the factors like resolution and magnification? could you pease also suggest me recommended lenses' focal length and aperture to build a telescope?
Asked by Somnath Pal
15th November 2015,
11:19 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
As shown above, a plane mirror is inclined at 30 degrees to horizontal and a horizontal ray is incident on it. What angle does the reflected ray make with the incident ray?
Asked by Aditya Great
3rd June 2015,
9:44 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
The focal lengths of the objective and the eyepiece of a compound microscope are 4cm and 6 cm respectively. If object is placed at distance 6 cm infront of objective lens, then maximum magnification of microscope is
1.) 31/3
2.) 62/3
3.)15/3
4.)10/3
Please explain.
Asked by Kb Aulakh
25th April 2015,
5:46 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
suppose while sitting in a parked car you notice a jogger approaching towards you in a side view mirror of R=2m. if the jogger is running at a speed of 5m/s . how fast the iimage of the jogger appear to moove when the jogger is (a)39m (B)29m (C)19m (D)9m away.
Asked by Kb Aulakh
6th March 2015,
7:51 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
derivation of youngs double slit expt?????
Asked by ARUN S
4th March 2015,
4:29 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
when is the magnification taken negative for telescope and compound microscope???
Asked by prativapradhan63
23rd February 2015,
10:18 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
the focal lengths of objective and eye lense of a microscope are 1.6 and 2.5 cm .the distance between the two lenses is 21.7cm.if the final image is formed at infinity the distance between the object and the objective lens is ?(ans.1.75cm)
Asked by Nidhi
26th December 2014,
1:42 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
- the diameter of moon is 3.5
10 3
(10 to the power 3) km and its distance from the earth is 3.810 5(10 to the power 5)km. it is seen by atelescope having the focal length of the objective and the eye piece as 4m and 10 cm respectively. the diameter of the image of the moon will be approximately ?(ans.20
).
10 3(10 to the power 3) km and its distance from the earth is 3.810 5(10 to the power 5)km. it is seen by atelescope having the focal length of the objective and the eye piece as 4m and 10 cm respectively. the diameter of the image of the moon will be approximately ?(ans.20).
Asked by Nidhi
25th December 2014,
12:27 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
the least resolvable angle by a telescope using objective of aperture 5 cm and light of 
=4000 A
(angestrom) is nearly? (ans. 1
50 sec. ) pls explain how?
=4000 A (angestrom) is nearly? (ans. 150 sec. ) pls explain how?
Asked by Nidhi
25th December 2014,
12:14 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
an achromatic telescope objective is to be made by combining the lenses of flint and crown glasses. this proper choice is ?
Asked by Nidhi
24th December 2014,
1:47 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
to remove the chromatic aberration the combination of lenses should be such that- A)Fr+Fv =0 (b) Fr>Fv (c) Fr<Fv (d.) Fr-Fv=0. [where Fr or Fv represents the equivalent focal lengths of the combination for red and violet colours.] please explain it clearly.?
Asked by Nidhi
24th December 2014,
1:41 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
1)to remove the chromatic aberration the combination of lenses should be. whare( Fr and Fv represent the equivalent focal length of the combination for red and violet colours). 2)an achromatic telescope objective is to be made by combining the lenses of flint and crown glasses.this proper choice is (ans.convergent of crown and divergent of flint) how? pls explain it. 3)an equilateral prism is placed on the prism table of spectrometer in the position of minimum deviation .if the angle of incidence is 60,the angle of deviation of the ray is (ans.60)
,the angle of deviation of the ray is (ans.60)
Asked by Nidhi
22nd December 2014,
2:35 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
a convex lens of focal length f produces a virtual image m times the size of the object .the focus will have magnification equal to- .
Asked by Nidhi
20th December 2014,
2:20 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
- three lenses L1,L2,L3 are givien each of focal length 10cm.an object is kept at 15cm in front of L1 .the final real image is formed at focus of L3.find the seperation between L1,L2,L3
Asked by sagarmanisha97
12th December 2014,
9:04 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
where can i find all the derivation, working of optical instruments related to this chapters????
Asked by Karishma
2nd October 2014,
1:44 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
What is the reason for considering the focussing of light inside a telescope tube as a problem with the reflecting telescope?.
Asked by MAANASI.M
28th September 2014,
9:52 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
a) Draw a ray diagram to show the working of a compound microscope. Deduce a expression for the total magnification when the final image is formed at the near point. b) A compound microscope has an objective of focal length 1 cm and an eye piece of focal length 2.5 cm.An object has to be placed at a distance of 1.2 cm away from the objective for normal adjustment.Find the angular magnification and length of the microscope tube.
Asked by Topperlearning User
13th June 2014,
9:06 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
(a) Draw a ray diagram showing the image formation by a compound microscope. Hence obtain expression for total magnification when the image is formed at infinity. (b) Distinguish between myopia and hypermetropia. Show diagrammatically how these defects can be corrected.
Asked by Topperlearning User
12th June 2014,
7:53 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
The diameter of the lens of a telescope is 0.61 m.Wavelength of light is 5000 Å. What is the resolution power of the telescope?
Asked by Topperlearning User
11th June 2014,
1:50 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
The focal length of the objective and eye piece of a telescope are 200 cm and 5 cm respectively.What is the maximum magnifying power of the telescope.
Asked by Topperlearning User
11th June 2014,
1:33 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
a. The focal lengths of both objective and eye lens of a microscope are 6 cm and 8 cm respectively. What is the magnification produced by it for an object placed at a distance of 8 cm from the objective?(Least distance of distinct vision, D = 25 cm)b. A microscope illuminated by UV light gives higher magnifications than that illuminated by visible light.Explain how?
Asked by Topperlearning User
11th June 2014,
12:33 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
An astronomical telescope consists of two thin lenses 50 cm apart. It has magnification of 9 at normal adjustment. Obtain the focal length of the two lenses.
Asked by Topperlearning User
11th June 2014,
12:25 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Draw a ray diagram of an astronomical telescope in the normal adjustment position. Write down the expression for its magnifying power. State two drawbacks of this type of telescope.
Asked by Topperlearning User
11th June 2014,
11:01 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Draw a labelled ray diagram showing the course of rays in an astronomical telescope,when the final image is formed at least distance of distinct vision. Write mathematical expression for its magnifying power.By increasing the diameter of the objective of telescope, we can increase its range,why?
Asked by Topperlearning User
11th June 2014,
10:50 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
A compound microscope with an objective of 2 cm focal length and an eye-piece of 4 cm focal length has a tube length of 40 cm. Calculate the magnifying power of the microscope, if the final image is formed at infinity.
Asked by Topperlearning User
11th June 2014,
10:47 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Draw a labelled ray diagram of a reflecting type telescope. Write its any one advantage over refracting type telescope.
Asked by Topperlearning User
11th June 2014,
10:35 AM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Two convex lenses of same focal length but
of aperture A1 and A2
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Define the term 'resolving power' of an astronomical telescope. How does it get affected on (i) increasing the aperture of the objective lens? (ii) Increasing the wavelength of the light used? Justify your answer in each case.
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Using the data given below, state as to which of the given lenses will you prefer to use as i) an eyepiece, ii) an objective to construct an astronomical telescope. Give reason for your answer. Lens Power Aperture L1 1 D 0.10m L2 10 D 0.05m L3 10 D 0.02m L4 20D 0.02m
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
A compound microscope has an objective lens of focal length 5 mm and eyepiece of focal length 4 cm. The separation between the two lenses is 24.5 cm.Where should an object be placed such that the final image is formed at infinity?
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
a. A person has normal eyesight. The person intends to read a book using a magnifying glass of focal length 8 cm. What is the closest and farthest distance at which the person can place the book, in order to read it using a magnifying glass?b. What is the difference between magnification and magnifying power of a magnifying glass?
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
In a compound microscope, an object is placed at a distance of 1.5 cm from the objective of focal length 1.25 cm. If the eye piece has a focal length of 5 cm and the final image is formed at the near point, estimate the magnifying power of the microscope.
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
Draw the labelled ray diagram for the formation of image by a compound microscope.Derive the expression for the total magnification of a compound microscope. Explain why both the objective and the eyepiece of a compound microscope must have short focal lengths.
Asked by Topperlearning User
4th June 2014,
1:23 PM
CBSE - XII Science - Physics - Ray Optics and Optical Instruments
An astronomical telescope, in normal adjustment position, has magnifying power 5. The distance between the objective and the eye-piece is 120 cm. Calculate the focal lengths of the objective and of the eye-piece.
Asked by Topperlearning User
4th June 2014,
1:23 PM
