Simply, loved your comment. Must thank you for your generous words. Happy to help you. Do well.

God bless you. Do well.

Thank you . ☺️

Happy to help you. God bless you .. 😊

Thank you for the very generous comment. Feel encouraged, elated & happy. Yes! Trying to continue ...

I am equally delighted dear Aryan. Do well. 😊

God bless you. Do well.

Thank you for the generous review. Happy to help you. The for formula R = 2 f is for a spherical mirror with small aperture ( plane mirror is its special case). Here, you have a solid convex lens + liquid Plano concave lens and a plane mirror). ☺️

@@parasharisir ah i seee. thanks for clarification!

Happy to help you. 😊 All the best.

Thank you for the excellent review. 👋

Happy to help you. 😊. Do well ..

Happy to help you. Do well.

Good to know the fact. Thank you. God bless you. Do well. 😊.

Happy to know, you benefited from my efforts..

Thank you for the appreciation. Sure! Will do more videos on practicals.

So happy to learn that my efforts are working for the good. Will bring more content with time .. Thank you for the appreciation. 😊

Sir you deserve this appreciation. Best of luck for upcoming content

Most welcome! Do well. 😊

... touch the convex lens with the wall opposite to a window and move it slowly away from it. Upside down image of the window will appear on the wall. Keep moving the lens away from the wall till you get its sharp image. Now measure the distance of the lens with the wall using a scale. This is the rough focal length of the convex lens. Think why?

All the best.

Thank you for the compliment. ☺️. Happy to help you. Do well ..

Happy to help you. Do well. God bless you.

All the best for today's practical. You are confident and assured about doing well. God bless you. Happy for you ..

@@parasharisir It's ur Generosity Sir ...Thanku For blessings Sir😊🙏My Practical Was Gone good And I was Surprised to see this one in my Luck⭐Thanku once again sir🙏

Thank you. Happy to help you 😊.

... doing an experiment? Errors are bound to occur. To minimize precautions are necessary. At school level, normally we accept errors up to 20% .

Wish you all the best for your practical examination. Keep kool. Do write result with units ..

Thank you ma'am for the encouraging words ..

Happy to help you. Do well. 😊

.. Agar pin convex lens ke focus per hai, to rays refraction ke baad parallel ho jaingi. Par parallel rays plane mirror se takrakar bapas convex lens girti hain aur jaha par pahele pin 📌 thi, usi jagah par eski real image ban jati hai aur parallax remove ho jata hai.

Yes. 😊

Thank you for your concern. Yes description is short. Have shared a link to download pdf of the experiment as well. Hope it helps. Anything else, please let me know.. Thank you.

Thank you for asking your doubt. I guess @ 10:10 !! Liquid lens is plano concave. Its focal length (f dash) got to be negative. f is positive also F is also positive.

Most welcome ☺️.

These are very tough and trying time. We never know about others. Have faith. I am telling you, he/ she is among the best in the world. Happy to help you. Do well.

@@parasharisir you're the best sir 🙏

Most welcome ! Please go ahead.

Happy to help. Do well.

Most welcome.

Yes, will do that. May be before 26th March.

Most welcome. Do well.

Yes you have the confidence. You will do well. God bless you .. ☺️

@@parasharisir thank you sir!! My exam went very well!

@@induuuu5338 Extremely happy for you . . ☺️

@@parasharisir sir, could you also upload strategies for studying for neet 2022 and term 2 physics board? I think it will be very helpful for aspirants like me. Thank you sir

@@induuuu5338Noted. Sure will do it ...

Thank you. 😊

Thanks you. God bless you. Do well.

@@parasharisir thank you sir

@@parasharisir sure sir

Thank you beta 😊😊😁😁

Thank you dear Harsh. God bless you.

Most welcome.

Happy to help.

Once you have found focal length of the lens (say f= 10 cm). Now you can use lens maker's formula with mhu = 1.5 to find radius of curvature R ( R1 = +R, R2= -R, f = 10 cm and mhu = 1.5 to find R. Usually the value of R is provided else you can calculate as suggested. Note. R= 2f for spherical mirrors with small curvature only. Not for lenses.

Most welcome. Happy to help. Do well..

Most welcome. Do well. God bless you.

@@parasharisir thank you so much!

Happy to help you. Do well.

Hello Aditi, Usually, the value of R is given. If not, then we need to calculate it using spherometer. I guess, this solves your issue. Have done video on spherometer with readings as well. Do well. God bless you ..

Thank you.

Usually it is given. If not, use (1) lens- makers formula for given convex lens (put mhu = 1.5, f = either rough focal length or value of f obtained in first part of experiment and R1= +R and R2= -R), second method use spherometer. If asked prefer first method. Calculate value of R now. Given R= 10 cm ....

Please specify f and f'.

@@parasharisir f is focal length of convex lens while f' is combined focal length (convex +plano concave)

@@visheshgupta1736 perfectly okay ... 😊

(i) Rough focal length is used to place needle above the lens as parallax is removed around this location only. It basically saves your time in locating the position of the image. (ii) Once you have found focal length after removing parallax as in (i), you know focal length of the lens ( say f= 10 cm). Now you can use lens maker's formula with mhu = 1.5 to find radius of curvature R ( R1 = +R, R2= -R, f = 10 cm and mhu = 1.5 to find R. Note. R= 2f for spherical mirrors with small curvature only. Not for lenses.

@@parasharisir thank u sir😊

@@parasharisir sir I recently tried this notation but I saw a difference in values of spherometer and lens maker's formula it came out to be 16 by formula and 11.23 by spherometer with the height 11.23 cm and focal length(rough) around 32 cm.

@@naman_bhavanabhatia5369 Please share one set of your readings by both the methods. Let me check for possible corrections. You can also check my video on spherometer which I have done somewhat differently.

@@parasharisir ok sir

Thank you sir! Always the best remark.

Thank you. Do well. ☺️

Thank you. Do well. God bless you.

Plz help sir

Please call at 9460068069 at around 7: 00 pm ..

.... R stands for radius of curvature of the concave surface of the liquid lens. It's measurement is in a direction opposite to incident ray.

@@parasharisir accha ok sir thank you🙏🏻

Thanks

Average distance = distance from optical center to tip of the needle = f

@@parasharisir ok thankyou.

Thank you ..☺️

Assuming you have completed the syllabus thoroughly:- 1. Write one sample paper once in three days Or two days as per need. Self evaluate it. Maybe you can request one out of five papers to your teacher for a full or partial assessment. Note: Sit for writing papers at 10 am to 1 pm if possible, preferably. Write complete paper. 2. Recalling and writing make part of your routine. 3. Do walk at least 30 min per day at home within the room Or at the terrace... All the best

happy to help. Do well. Sharing the link here as well as in the description. drive.google.com/file/d/1TBuH9dSsCHqCxmnFXIesxnjEPx9xGBk2/view?usp=sharing

Statement 1. Across a resistor when I is changed, V also changes ( V depends on I). Statement 2. When U is changed, V also changes ( 1/V - 1/U = 1/F). Here, image is always formed at focus. No variable and hence same readings.

@@parasharisir thank you,sir. explanation of the practical with simple understanding of concepts is great .🙏🙏🙏🙏🙏🙏🙏🙏

Usually, value of R is given. If not use mhu = 1.5 and value of rough focal length to calculate it using lens maker's formula ..

1. Find rough focal length of the convex lens (say 10 cm). 2. Place lens over the plane mirror and bring needle over it ( ensure it is roughly 10 cm over it say at 8 cm above the lens. 3. Now join tip to tip while looking in to the lens and move the needle slowly in the upwards direction. You will notice at some point close to 10 cm both needle tip and image move together.

@@parasharisir thank you sir!! Parallax is removed by moving the pin upwards aur adjusting the mirror?

@@visheshgupta1736 mirror is slided to join tip of object to tip of image. 1. For f=10 cm place needle 8 cm over the lens and the join tip to tip. You can see that there is parallax by moving your head left and then right. Now move needle slowly in upwards direction, while moving your head towards left and right. You will observe that at one point both object needle and image needle move together. We say that parallax has removed.....

@@parasharisir thanks sir. Parallax removing was a big headache for me in all exp. As it is always responsible for accurate readings and I cant do it. But now I understood so much well.thank you you teachings will make my practical good.

Biconvex has two surfaces to covering the material. First Surface facing the incident ray has positive radius of curvature, while the other has negative radius of curvature. Water lens is plano concave lens. The first surface (in contact with the lower surface of convex lens) has negative radius of curvature.

@@parasharisir got it sir

a) 10.1 cm is distance of needle tip from the top of convex lens.. b) -11.5 is the radius of curvature of the lens which is usually given. Else we need to use spherometer to measurement radius of curvature of the lens. c) couldn't trace 10.3 cm ..

@@parasharisir sir convex lens ki focal length kitni hoti he

.. from the optical center of the lens to its primary focus. In this experiment from the center of lens till the tip of the needle (once parallax is removed).

@@parasharisir thank you so much sir . I really happy with your answers.

dōitashimashite !

Thank you. Do well.

Cannot happen. Keep patience.

@@parasharisir sir ho gya galat external ne bola ki ye galat hai 😭😭

@@ketan5272 Dear Ketan, working since last 32 years and training teachers as well. I repeat it can't happen. Please look at the answers to various queries as well.

@@parasharisir sir aapka explanation correct hai lekin ma'am ne bola ki ye practical hai aap itna accurate nhi likh sakte toh teeno value me changes karke likhna padega

Hi !

.... Have decided to complete subject content in Indian English first. Will do videos of similar type in Hindi as well....

Sorry. Hindi is the most commonly spoken language but not the national language 🙏

There is nothing such as national language in India. Hindi is one of the official languages of India.

Please wait. Will do it.

Happy to help. Do well ..

Happy to help. Do well ..

Most welcome.

Welcome dear Aftab.

Most welcome. Do well. ☺️. God bless you.