Physics, Class XI Chapter: Properties of fluids Topic: Surface Tension part1 Classroom lecture by Pradeep Kshetrapal. Language : English mixed with Hindi.
Cohesive forces are acting inward on surface, which have intention to decrease its surface area or volume of the liquid, so liquid gets pressurized(Excess Pressure) which in turn have intention to increase the volume or surface area, makes the surface to be stretched, which in turn create tangential force.
Wow. saab. What a clarity in your explanations. Surpasses all the foreign videos explaining the same concept. I am sure you are teaching IIT aspirants.
Sir my name is Surbhi Chauhan n I like Physics very much but i belong to a very small town where I cannot find a good teacher but from ur videos i m getting many benefits . Thanx sir u r my mentor . PLz sir teach numericals also to large extent bcz they r gonna help us in competition
for people who're confused about the force acting tangetial and perpendicular..the force is acting TANGENTIAL to the SURFACE OF LIQUID and PERPENDICULAR to the line which you consider.
Dear sir. I have done PhD in physics.. And I also tech. Physics.. Iam very thank ful to you for your nicely delivered lectures.. I learned a lot from you
***** Sir,In the beginning of lecture you have said that surface tension is parallel to the surface.But while solving U-tube wire frame problem,you applied a force F which was perpendicular to surface and was balancing surface tension force....why?
Brilliant explanation sir. Try to advertise your channel. By this it will get a great success and many students become known to your channel. By this many other students can see how a great teacher can increase interest in physics automatically.😁👍👍
sir here you have said that the dimensions of surface energy is the same as work done ,i.e., joules but in your notes it is given that it is joules per metre square
sir 1 question hai apne bataya ki agar hum kisi molecule ko uper leke jate hai to potential energy hoti hai par agar hum sea ki baat kare to sea ke surface pe bbhe molecule hote hai to Iska matluv unke pass bhi potential energy hoti hai to bo energy khan se aati hai
Amazing video and amazing explanation for surface tension phenomenon. Your video has been very helpful. Kindly keep up the good work and keep it free as your knowledge will surely benefit many needy students. I teach my kid myself and have a good understanding of Physics topics. However, I have been really moved that you have chosen to upload wealth of videos for free. Thank you.
sir in deriving the relation between surface tension and surface energy , it is given that in order to slide the wire in the frame we need to apply opposite force equal to the surface tension . But if that is the case shouldn't the wire remain in equilibrium of the two opposite forces?and the wire at the same position ? All i want to ask is that why don't we apply force slightly greater than the force due to surface tension?
sir in d concept of cohesion and adhesion u said dat d water first comes up and sticks to glass because of larger adhesive force.nd den because of surface tension , it will try to reduce its area..den u said water molecules will go up and thus try to become plane...but i think due to that...its area will increase even more,,i think it shud come down.
Sir we read in Chemistry that in Surface tension molecules inside the liquid attracts the liquid molecules on the surface. The net force is acting inward, perpendicular to the surface but here you said that it is acting tangentially to the surface. Can you please explain? I'm so confused.
Sir, at about 6:40 u said particles tend to move tangential to reduce surface area.Sir,for the same reason they should move towards centre to reduce surface area
Respected sir, excellent video and great intention, just wish to add some criticism for improvement. You explained surface tension as the force in the plane of the surface itself, the spring model you mentioned somewhere projects such an image. But, it is rather due to the asymmetric force distribution on surface molecules whose resultant is pulling down the surface molecules towards the interior. Though, your explaination is best in any way..but it is incorrect to assume such a force distribution on surface molecule as you described. The balloon analogy is correct in terms of efforts to minimize energy, but even it confirms the assumption that the force entirely likes on the surface itself, which is correct only for the balloon because the balloon is inflated and filled with different matter (air). Such can be the case of thin films, but even the thickness of thin films is more than one molecule anyway.
plz help me how to come with solution to this problem? The systolic pressure in a major artery is measured at 115 mmHg. What is the net force on a 1 cm2 section of the arterial wall if the (absolute) pressure in the tissue outside the arterial wall is 109 kPa? (Patm = 101.3 kPa) Answer: 0.76 N
sir in the process of wetting force of adhesion is greater than cohesion.. so in tht case the liquid drop doesn't tend to reduce their are r8? n surface tension arises due to cohesive force hence wetting cannot be considered as a property of suface tension r8?
you said that S (surface tension) is not force but force per unit length...then at 21:20 you show that the force acting on needle is S....Please clarify.
thank u so much sir.......from 25th November.... i hav my prelims nd u had done a biggest favor by uploading this chapter.............plz do upload other parts of this chapter.......nd i know its not possible to upload all parts before 25th or till 25th ....i ll learn little amount of this chapter nd it wud be enough for me to write at least something and other parts i ll learn from here after prilims.....for now this part is enough for me ...thnk u again.
Sir you are following hc verma while teaching or any other book.If u can tell us then it would be easy for us to first read the concept and then come to the class.Hope u will be helping us.
sir,you told that surface tension is due to the net downward force on the molecules of the surface, but molecules my school teacher says that this concept is wrong. he says that if there is a net downward force then the surface should have an acceleration and therefore it will collaspe. I AM TOTALLY CONFUSED.
+Pradeep Kshetrapal Hello there, the whole concept behind defining the surface tension from mechanical stress point of view has a great problem in it. One of the best example is the question raised by sanju paul and the very next problem is the vertical component of surface tension (not described by Young in his famous equation) between liquid and air which is an "unbalanced force" within the system. So I think its better to concentrate on the energy concept of surface tension rather than the mechanical definition. Note: You define surface tension to be the characteristic of liquids. But is that true? So how would you describe Youngs law? Please update your lecture.
Sir ,i was doing some surface tension numerical .i couldn,t understand what to take (L) in the formula s=F/l...Is it breadth,depth,length or perimeter...sir please help And sir what is free surface??
Surface ka molecule jo andar ki taraf kheechaav mehsus karta hai wo kis wajah se? uski lower energy state me jaane ki property se ya phir andar ke molecules ke cohesion ki wajah se?
Milind Pateriya surface energy work done against surface tension hoti hai.. Ye gravitation potential energy ki tarah hai.. Gravity object ko neeche attract karti hai par gpe height ke saath badhti hai
As a needle is kept on the water the molecules of water will get aside as needle occupies some space and surface tension has a tendency to minimize surface area so the molecules of water will try to contract and doing so tangential force is applied to needle then by applying components cos theta balances the weight of the needle and sin theta cancels out so the needle floats.
The force due to film is 2Tl because we have two surface 40:10
wow. sir u teach so good and above that u are such a good human being. #Respect sir.
Excellent explanation sir!
I am a huge fan of your online lectures. Thank You very much for this video... :)
Ok
Cohesive forces are acting inward on surface, which have intention to decrease its surface area or volume of the liquid, so liquid gets pressurized(Excess Pressure) which in turn have intention to increase the volume or surface area, makes the surface to be stretched, which in turn create tangential force.
This video is bringing larger adhesion from physics to me
For so thanks a lot, Sir
Wow. saab. What a clarity in your explanations. Surpasses all the foreign videos explaining the same concept. I am sure you are teaching IIT aspirants.
Hey what are u doing now a days
Sir my name is Surbhi Chauhan n I like Physics very much but i belong to a very small town where I cannot find a good teacher but from ur videos i m getting many benefits . Thanx sir u r my mentor . PLz sir teach numericals also to large extent bcz they r gonna help us in competition
best physics teacher I have ever come across
for people who're confused about the force acting tangetial and perpendicular..the force is acting TANGENTIAL to the SURFACE OF LIQUID and PERPENDICULAR to the line which you consider.
me too also have this same problem..
+darshan joshi .-. i see...
+Mitali Patil tangential means on the surface at any angle dirn to force or velocity and perpendicular means normal/90/or 2 centre of gravity
Dear sir. I have done PhD in physics.. And I also tech. Physics.. Iam very thank ful to you for your nicely delivered lectures.. I learned a lot from you
I love the way you teach sir...
after watching your lecture classes physics became my favourite subject...
Always salute you sir!!!!!!!
sir u r the bst tchr i had ever seen.
sir thanks a lot .
***** Sir,In the beginning of lecture you have said that surface tension is parallel to the surface.But while solving U-tube wire frame problem,you applied a force F which was perpendicular to surface and was balancing surface tension force....why?
lucky guys....
got an excellent mentor to achieve milestone
your notes and lectures are great and concept clearing....thankyou
Brilliant explanation sir. Try to advertise your channel. By this it will get a great success and many students become known to your channel. By this many other students can see how a great teacher can increase interest in physics automatically.😁👍👍
Thank you sir ... I am engineering student preparing for gate . I find your videos very useful to strengthen my basics .
very good experience👍👍
sir i have huge respect for you may you live in our heart forever
brilliant. and also you are great teacher.
sir here you have said that the dimensions of surface energy is the same as work done ,i.e., joules but in your notes it is given that it is joules per metre square
Awesome....!!!! Sir you taught awesomely
sir 1 question hai apne bataya ki agar hum kisi molecule ko uper leke jate hai to potential energy hoti hai par agar hum sea ki baat kare to sea ke surface pe bbhe molecule hote hai to Iska matluv unke pass bhi potential energy hoti hai to bo energy khan se aati hai
Sir we rub the ballon with the hair so that it stick to the wall.Do we do it to increase adhesion force between molecules of wall and ballon
Amazing video and amazing explanation for surface tension phenomenon. Your video has been very helpful. Kindly keep up the good work and keep it free as your knowledge will surely benefit many needy students. I teach my kid myself and have a good understanding of Physics topics. However, I have been really moved that you have chosen to upload wealth of videos for free. Thank you.
sir in the case of work done dw should be equal to 2w×∆l because here liquid has two free surfaces
Sir you are great and your are doing such a wonderful job thank you sir its very helpful for us
sir in deriving the relation between surface tension and surface energy , it is given that in order to slide the wire in the frame we need to apply opposite force equal to the surface tension . But if that is the case shouldn't the wire remain in equilibrium of the two opposite forces?and the wire at the same position ? All i want to ask is that why don't we apply force slightly greater than the force due to surface tension?
+Parth Patil friend, the force is applied slightly greater only. but for simplification, we neglect that slight extra force applied.
Bahut hi badhiya explain kar rahe hai sir .i became your fan.
it's really oosum Sir.. ur xplainations are too good
it's good and the explanation is excellent
sir your explanation is very clear..nd is very heplful..for all the topics..thankyou..
Nyc video..
ur work is worth appreciation..
sir in d concept of cohesion and adhesion u said dat d water first comes up and sticks to glass because of larger adhesive force.nd den because of surface tension , it will try to reduce its area..den u said water molecules will go up and thus try to become plane...but i think due to that...its area will increase even more,,i think it shud come down.
Sir we read in Chemistry that in Surface tension molecules inside the liquid attracts the liquid molecules on the surface. The net force is acting inward, perpendicular to the surface but here you said that it is acting tangentially to the surface. Can you please explain? I'm so confused.
Sir, at about 6:40 u said particles tend to move tangential to reduce surface area.Sir,for the same reason they should move towards centre to reduce surface area
really u made it too simple to understand
Respected sir, excellent video and great intention, just wish to add some criticism for improvement. You explained surface tension as the force in the plane of the surface itself, the spring model you mentioned somewhere projects such an image. But, it is rather due to the asymmetric force distribution on surface molecules whose resultant is pulling down the surface molecules towards the interior. Though, your explaination is best in any way..but it is incorrect to assume such a force distribution on surface molecule as you described. The balloon analogy is correct in terms of efforts to minimize energy, but even it confirms the assumption that the force entirely likes on the surface itself, which is correct only for the balloon because the balloon is inflated and filled with different matter (air). Such can be the case of thin films, but even the thickness of thin films is more than one molecule anyway.
plz help me how to come with solution to this problem?
The systolic pressure in a major artery is measured at
115 mmHg. What is the net force on a 1 cm2
section of the arterial
wall if the (absolute) pressure in the tissue outside the arterial
wall is 109 kPa? (Patm = 101.3 kPa) Answer: 0.76 N
Very nice sir.... Superb explanation
sir very nice vdo n ur explanation awsm....👍👍
Sir I am from Pakistan I like your method of teaching ......💗💗💗💗
I like your method of explanation how to teach students in easy way
sir if needle is float by surface tension then why any other object sink on which surface tension work
Sir, as we know tension force acts in outward direction while compression in inward direction. So, why molecules of liquids attract each other!!
Best understood physics by him
Sir you are outstanding
CONGRATS FOR HALF A MILLION SUBSCRIBERS SIR.....THANK YOU....
Sir why will we add force by surface tension to the apparent weight of submerged body?
sir in the process of wetting force of adhesion is greater than cohesion.. so in tht case the liquid drop doesn't tend to reduce their are r8? n surface tension arises due to cohesive force hence wetting cannot be considered as a property of suface tension r8?
Water, methyl cyanide or methanol which among the following have highest surface tension at room temperature and why??
you said that S (surface tension) is not force but force per unit length...then at 21:20 you show that the force acting on needle is S....Please clarify.
best teacher...masterGuru GLAD!!
Good work
Sir you say tht due to surface tension tends to decrease their area? y liquids tend to reduce the area? what is the benifit of reducing the area?
nice lectur sir
thank u so much sir.......from 25th November.... i hav my prelims nd u had done a biggest favor by uploading this chapter.............plz do upload other parts of this chapter.......nd i know its not possible to upload all parts before 25th or till 25th ....i ll learn little amount of this chapter nd it wud be enough for me to write at least something and other parts i ll learn from here after prilims.....for now this part is enough for me ...thnk u again.
if feel shocked when some people write that pradeep sir don't know how to teach
sir the bottom layer also does not have any layer beaneth it ...so does it have any energy'
'??????????????
mind blowing work sir
Sir you are following hc verma while teaching or any other book.If u can tell us then it would be easy for us to first read the concept and then come to the class.Hope u will be helping us.
ধন্যবাদ স্যার। খুব ভালো উপস্থাপন ছিল। ভালো লেগেছে 😃👌👌
sir,at about 15:48 u said d reason for the gathering of hairs of brush but wat about it wen dipped in water ,they spread out.what is d reason for it?
sir,you told that surface tension is due to the net downward force on the molecules of the surface, but molecules my school teacher says that this concept is wrong. he says that if there is a net downward force then the surface should have an acceleration and therefore it will collaspe. I AM TOTALLY CONFUSED.
***** but sir, there should be a net upward force to balance the net downward electromagnetic inter molecular force on a molecule on surface????
+Pradeep Kshetrapal Hello there, the whole concept behind defining the surface tension from mechanical stress point of view has a great problem in it. One of the best example is the question raised by sanju paul and the very next problem is the vertical component of surface tension (not described by Young in his famous equation) between liquid and air which is an "unbalanced force" within the system. So I think its better to concentrate on the energy concept of surface tension rather than the mechanical definition. Note: You define surface tension to be the characteristic of liquids. But is that true? So how would you describe Youngs law? Please update your lecture.
sir i cant download class 11th PHY notes frm ur website ?? plz help me how can i download it ???
Awesome!!!
Nice teaching skill.
nicely explained sir please Maharashtra SB ke topic bhi explain kijiye
thank you so much sir !!!!! your vedios are very nice .
ur videos made me learn a lot
sir why bubbles are form on river water or on any another source of water sir please reply please
sir excellent explanation i like it
Sir...u said in class 74 that u will discuss about measurement of pressure with barometer but you dint explain that in 75th class or 76th class sir...
Sir ,i was doing some surface tension numerical .i couldn,t understand what to take (L) in the formula s=F/l...Is it breadth,depth,length or perimeter...sir please help
And sir what is free surface??
***** sir is surface tension force act only on free surface
#Excellent
Sir one question
Why SLS have 40 HLB Value
Plzzz give answer sir
sir why you doesn't take l as length while calculating surface energy ?
Sir, ihave never seen such explanations of these topics..heads off to u..when u will upload lectures of Bernauliis chapter?
Why does viscosity exist in gas while surface tension doesn't ?
+Robert Karna because gasses have slight intermolecular force of attraction, but they dont form any surface, hence no surface tention
Sir what is the reason for paintbrushes to spread inside the water when it is dipped?
Pranav Pramod because in water surface tension decreases
sir this video is very best
Sir aap itna accha padhana kaha se sikhe . who is your inspiration ?
Surface ka molecule jo andar ki taraf kheechaav mehsus karta hai wo kis wajah se? uski lower energy state me jaane ki property se ya phir andar ke molecules ke cohesion ki wajah se?
hi bro it is beacause of a cohesive force bw the surface molecule and their lower molecule the attractive force of lower molecule not balanced .
sir surface energy matlab area Ko Badhana but surface tension reduces the area so plzz reply
Milind Pateriya bhai tu kissi r se puch...ye nhi bta pa rhe
Milind Pateriya surface energy work done against surface tension hoti hai.. Ye gravitation potential energy ki tarah hai.. Gravity object ko neeche attract karti hai par gpe height ke saath badhti hai
Sir please give me one answer
Why raindrop is spherical
Sir u r genious..
sir i wanted to know about the meniscus through vector
you are superb
Sir, why needle when placed gently in water, floats???
As a needle is kept on the water the molecules of water will get aside as needle occupies some space and surface tension has a tendency to minimize surface area so the molecules of water will try to contract and doing so tangential force is applied to needle then by applying components cos theta balances the weight of the needle and sin theta cancels out so the needle floats.
Nice...
sir can u upload different questions on circuits and potentiometer.
sir wen u said f=sl, it should be f=s2l becuz a film has two surfaces
please make it clear
***** Sir, so does that mean that Force = Surface Tension / Total Length ?
hello sir
what meaning of capillary rise in surface tension
sir when relating surface enrgy with surface tension the force due to surface tension should be equal to f=2×s×l
Is this video good for NEET point of view SIR......?
Thank you Very Much Sir....
Sir,i wanted to know that if u cud suggest a chemistery teacher who is having videos like u on you tube..!! thanx.!!
sir is L the perimeter of surface ?
Sir i am watching u frm nepal.like it
thnx sir,i want notes for this chapter.
Hello sir i m ur big fan sir i m unable to find ur presentation on parachor