Sir I really want to tell you that you're a gem of a teacher sir...I tried so many different videos but it never worked for me in lab... However I'm sure now I will be able to do it... Thank you so much sir, am grateful to you
Simple , To the point , correct calculation , Clarity in concept . Excellent sir , Just magnificent . Very helpful during these unprecedented times . Keep up the good work .
There are so many videos are there over here but this one is seriously best one......Your way of explaining is absolutely perfect sir....😊 Thank you 💐💐
Thank you it was a great and simple way of explanation. I had personally tried to do this practical, it was quite hard without proper knowledge.Tomorrow is my board practical now I am confident with all of the 4 experiments.
hey there! Your way of explanation was on point and really loved it! But I've got one doubt about it, why can't we use R=2f formula to find the radius of curvature??
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). ☺️
Sir your explanation was so great and simple I really can't tell. Watching the whole video made me endure how well you have explained it. Thank you so much pls keep coming up with such content
Sir I Am Very Glad To Find Such Good Representative Video Of Practical🙏😊Thanku Sir Today Is My Practical And I Was Just Worried About This Practical Only...U Have Cleared My All Worries⭐🤗
@@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🙏
sir the explanation was really great, and your voice is soo humble like i understood each and every word that you said. I as a student really really appreciate the way you explain everything sir, thank you soo much for sharing such a great explanation with us 😃😃
(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 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.
Sir how to find focal length of convex mirror using a convex lens.I can't find a video of yours. It is the hardest practical .I don't know anything and my practical is tomorrow .Plzz help
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.
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.
.. 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.
@@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
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.
... 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?
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 ..
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
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.
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 ....
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.
@@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.
happy to help. Do well. Sharing the link here as well as in the description. drive.google.com/file/d/1TBuH9dSsCHqCxmnFXIesxnjEPx9xGBk2/view?usp=sharing
19:44 same readings lene bolte ho sir aap Aapke wajhe se mera board practical galat ho gya aaj😭 External ne mujhe bola same readings galat hai alag reading aani chahiye 😭😭😭😭
@@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
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 ..
.. 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).
O.M.G 🤯🤯🤯. This much simple and great explantaion and so much less views. You should have millions of views and subscribers too sir.
New subscriber!
Simply, loved your comment. Must thank you for your generous words. Happy to help you. Do well.
Sir I really want to tell you that you're a gem of a teacher sir...I tried so many different videos but it never worked for me in lab... However I'm sure now I will be able to do it... Thank you so much sir, am grateful to you
God bless you. Do well.
Simple , To the point , correct calculation , Clarity in concept .
Excellent sir , Just magnificent .
Very helpful during these unprecedented times .
Keep up the good work .
Thank you for the very generous comment. Feel encouraged, elated & happy.
Yes! Trying to continue ...
There are so many videos are there over here but this one is seriously best one......Your way of explaining is absolutely perfect sir....😊
Thank you 💐💐
Thank you . ☺️
Finally someone who could explain this experiment.... It was so easy than I thought .... Thank you very much sir... 🤝🤝
Happy to help you. God bless you .. 😊
Its great to have a teacher like you sir who explain everything so well
I am equally delighted dear Aryan. Do well. 😊
Thank you it was a great and simple way of explanation.
I had personally tried to do this practical, it was quite hard without proper knowledge.Tomorrow is my board practical now I am confident with all of the 4 experiments.
Happy to help you. 😊 All the best.
hey there! Your way of explanation was on point and really loved it! But I've got one doubt about it, why can't we use R=2f formula to find the radius of curvature??
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!
I afraid of this particular experiment but after your video I'm very confident now. Thanks a lot sir.
God bless you. Do well.
Crystal clear sir ready for practicals
Very helpful videos🙏🏼🙏🏼🙏🏼
Happy to help you. Do well.
No word , simply easy and full explained
Happy to know, you benefited from my efforts..
No one ever explained principle but sir you did it thanks
Good to know the fact. Thank you. God bless you. Do well. 😊.
Thank You Sir ❤❤❤
Most welcome!
Sir your explanation was so great and simple I really can't tell. Watching the whole video made me endure how well you have explained it. Thank you so much pls keep coming up with such content
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
Great demonstration. In-depth and clear explanation. 👍👍👍
Thank you for the excellent review. 👋
Sir error is important in this practice? please reply
... doing an experiment? Errors are bound to occur. To minimize precautions are necessary. At school level, normally we accept errors up to 20% .
Thank you so much sir for explaining this experiment in such a simple and easy way. It really helped me a lot 🙏
Happy to help you. 😊. Do well ..
Sir I Am Very Glad To Find Such Good Representative Video Of Practical🙏😊Thanku Sir Today Is My Practical And I Was Just Worried About This Practical Only...U Have Cleared My All Worries⭐🤗
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🙏
sir the explanation was really great, and your voice is soo humble like i understood each and every word that you said. I as a student really really appreciate the way you explain everything sir, thank you soo much for sharing such a great explanation with us 😃😃
Sir tomorrow is my board practical exam ,much worried as not done before but thank for lovely explanation done with experiment. Thank u sir
Wish you all the best for your practical examination. Keep kool. Do write result with units ..
Such a good voice you have... Thanks for the best explanation sir ..
Thank you for the compliment. ☺️. Happy to help you. Do well ..
As always ..I have only one thing to say ...videos Jabardasth ha.. it will be great help to class 12th students
Thank you sir! Always the best remark.
Thank you so much sir..Kal mera practical it helps alot🙏
All the best.
Our teacher has given the formula n=2-f/f' is it correct tooo?
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 ... 😊
Sir can we just double the Rough focal length to find the radius of curvature so as to avoid the calculation of spherometer
(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
Amazing 👏🏼👏🏼👏🏼👏🏼 sir plz do all other practicals of class 12..
Thank you for the appreciation. Sure! Will do more videos on practicals.
Sir how to find focal length of convex mirror using a convex lens.I can't find a video of yours. It is the hardest practical .I don't know anything and my practical is tomorrow .Plzz help
Plz help sir
Please call at 9460068069 at around 7: 00 pm ..
excuse me, sir. I have one doubt. Why have you written same reading thrice?
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 .🙏🙏🙏🙏🙏🙏🙏🙏
Thanku so much sir , It is now easy for me 👍
Happy to help you. Do well. God bless you.
Sir why there is -ve sign in the formula of finding the f'
.... 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🙏🏻
Sir what is the description for this experiment
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.
Sir why do we need to find the average focal length?
Average distance = distance from optical center to tip of the needle = f
@@parasharisir ok thankyou.
Convex lens ma image real or erect bnti to parallex error Kesy romove hoga
.. 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.
My exam is tmmrw sir, and I just wanted to say thank you so much! I've understood everything and hoping to do well tmmrw
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 ...
Sir why did you take - for f dash focal length
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.
Sir what is the rough focal lenght of the convex lens
... 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?
sir i dont undersand how u calculated R ??....Your way of explanation was on point and really loved it
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 ..
Thankyou very much sir i am your new subscriber
Most welcome ☺️.
Sir to score 95 plus in physics which book should I follow with ncert or will the ncert be enough
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
Thankyou so much sir for your help ❤️❤️😊
Happy to help you. Do well. 😊
Thank u so much from the bottom of my heart sir 😊
Respect 🙏
Most welcome! Do well. 😊
very well explained sir
Thank you beta 😊😊😁😁
Thank you dear Harsh. God bless you.
Thanks so much sir lovely explanation understood it ☺️
Most welcome. Do well. God bless you.
@@parasharisir thank you so much!
Wow sir from Bangladesh ❤
Most welcome. Do well.
Perfect physics pratical
Thank you. Happy to help you 😊.
Sir R kha se laye hai..
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.
Sir i want to say something can i?
Most welcome ! Please go ahead.
Very well explained Parashari Sir !👌👍
Thank you ma'am for the encouraging words ..
how to calculate radius of curvature
2 f ?
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 ....
thank you sir for such a easy explanation
Happy to help. Do well.
Clear explanation...💯💯
Thank you.
Well presented :)
Thank you. 😊
Sir, Can u pls do a video on pn junction diode experiment
Yes, will do that. May be before 26th March.
Sir this was really amazing thank you so much and keep it up
Thanks you. God bless you. Do well.
@@parasharisir thank you sir
@@parasharisir sure sir
Amazing sir
Thank you. Do well. God bless you.
Sir thank you very much
Happy to help. Do well ..
Wonderful explanation!
Thank you. Do well. ☺️
Thank you sir ☺️
Most welcome.
How to remove parallax?
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.
Thnku so mucch sir
Most welcome. Happy to help. Do well..
Thank you so much sir ☺️
Happy to help you. Do well.
Thank you sir
Happy to help.
Radius of convex lens should be positive
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
Amazing sir 👍👍👍👍
Thank you ..☺️
Sir please pdf of this topic
happy to help. Do well. Sharing the link here as well as in the description.
drive.google.com/file/d/1TBuH9dSsCHqCxmnFXIesxnjEPx9xGBk2/view?usp=sharing
Nice
Most welcome.
10.5 kaha se agya
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 ..
Best
Thanks
19:44 same readings lene bolte ho sir aap
Aapke wajhe se mera board practical galat ho gya aaj😭
External ne mujhe bola same readings galat hai alag reading aani chahiye 😭😭😭😭
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
Sir 10.3 kaha se aaya
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.
arigato gozaimashita
dōitashimashite !
There are so many videos but this one is the best
Thank you. Do well.
sir you can use hindi !!!! We are in india!!!!! Hindi is our national language
.... 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.
BRUH!
Hi !
Hindi me bolo
Please wait. Will do it.
Thank you sir
Most welcome.
thank you so much sir
Happy to help. Do well ..
Thank you sir
Most welcome. Do well. ☺️. God bless you.
Thank you sir
Welcome dear Aftab.