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What is meant by cyclic process. Give schematic representation of heat engine.

Posted by Ajina Johnson 7 years ago

1 answers

Cyclic process-The process in which the system undergoes a series of changes and come back to its initial position OR The process in which the initial and final condition of the system are same.(different in different books)

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Why apple fall down the earth , does gravity is inside core of earth ?

Posted by Damodar Anmol 7 years ago

CBSE > Class 11 > Physics

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Equation for streamline flow

Posted by Kenny Nongbri 7 years ago

CBSE > Class 11 > Physics

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3 difference b/w streamline and laminar flow

Posted by Talib Gazi 7 years ago

CBSE > Class 11 > Physics

1 answers

Yogita Ingle 7 years ago

Streamline flow: : The flow of a fluid is said to be streamline (also known as steady flow or laminar flow), if every particle of the fluid follows exactly the path of its preceding particle and has the same velocity as that of its preceding particle when crossing a fixed point of reference.
Turbulent flow: The flow of a fluid is said to be turbulent or disorderly, if its velocity is greater than its critical velocity. Critical velocity of a fluid is that velocity up to which the fluid flow is streamlined and above which its flow becomes turbulent. When the velocity of a fluid exceeds the critical velocity, the paths and velocities of the fluid particles begin to change continuously and haphazardly. The flow loses all its orderliness and is called turbulent flow.

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Diff bet. Vector n scalar quantities? Atleast 3

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

1 answers

Veena Singh☺️? 7 years ago

Quantities having magnitude and direction both are called vector quantities. EX- velocity Quantities having only magnitude and no direction are called scalar quantities . EX- speed

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A concave mirror is held in water.what would be the change in the focal length of the mirror?

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

3 answers

Vaibhav Goel 7 years ago

There is no change in the focal length when a concave mirror is held in water.

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Manikandan Mani 7 years ago

When a light passes to mirror is get reflected as same as in air as well as water medium

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Manikandan Mani 7 years ago

There is no change in the focal length when a concave mirror is held in water .

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How can we see a virtual image when it cannot be obtained on a screen?

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

2 answers

Meghna Sharma 7 years ago

No, the correct answer is True,a virtual image cannot be taken on screen. But our eye lens forms a real image of (virtual image acting as virtual object)on the retina of our eyes. Thanks for ur answer.

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Navdeep Singh 7 years ago

Behind the mirror or lens as we see everyday in a mirror

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It is easy to pull than to push a lawn roller.why?

Posted by Yash Sharma 7 years ago

CBSE > Class 11 > Physics

1 answers

Priyanka Kumari 7 years ago

It is easier to pull a lawn roller than to push it. Explain using the resolution of forces. Answer: The force applied to move a body depends upon effective force applied on it including its weight. As effective weight in the case of pulling is less than in the pushing, less force is required in pulling.

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Define young modulus of elasticity. Given its unit and dimensions

Posted by Gudda Kapil 7 years ago

CBSE > Class 11 > Physics

1 answers

Meghna Sharma 7 years ago

It is the ratio of normal stress to the longitudinal strain within the elastic limit. Unit- newton per metre square Dimensions- [ML(-1)T(-2)]

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Difference between rigid and non rigid body on the basis of modulus?

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

1 answers

Aashir Arham ⚽?⚽ 7 years ago

Young’s Modulus Elasticity shows the stiffness of a material. If a material has low Elasticity such as a rubber band you can deform it easily. If a material has high Elasticity such as steel, it is hard to deform. Now rigid body can also be defined with Young’s Modulus. A rigid body is such a body that it has infinite Elasticity. All non rigid materials have different stifnesses(Elasticity), like the previous example of rubber and steel.

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Difference Between rigid and non rigid body?

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

1 answers

Aashir Arham ⚽?⚽ 7 years ago

When force is applied on a rigid body, there will be no change in the shape or size of the rigid body. In case of a non rigid body the force will distort shape and/or size of the body.

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Expression for excess of pressure inside or outside the bubble

Posted by Sunny Agarwal 7 years ago

CBSE > Class 11 > Physics

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A gas filled in a vessel at a certain temperature and pressure. At the same temperature more gas is filled in the vessel so that its mass increases by 40%. Calculate the ratio of initial and final pressure

Posted by Ayush Gupta 7 years ago

CBSE > Class 11 > Physics

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Calculate the ratio of change in the mass of the molecules of a gas to the initial mass ,if its speed is reduced to half and the ratio of initial and final pressure is 3:4

Posted by Ayush Gupta 7 years ago

CBSE > Class 11 > Physics

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Derivation of Len's formula

Posted by Ratnam Tripathi 7 years ago

CBSE > Class 11 > Physics

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If a point mass m is at a distance x from the centre of a sherical shell of mass M and radius R>x what is the force between them

Posted by Mahek Deep 7 years ago

CBSE > Class 11 > Physics

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why cyclist bend during taking a curve

Posted by Deepti Bhatia 7 years ago

CBSE > Class 11 > Physics

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5 differences between vector and scalar quantities

Posted by Meghna Sharma 4 years, 9 months ago

CBSE > Class 11 > Physics

1 answers

Sia ? 4 years, 9 months ago

A scalar quantity has only magnitude, but no direction. Vector quantity has both magnitude and direction. Every scalar quantity is one-dimensional. ... For example, the dot product of two vectors gives only scalar; while, cross product, summation, or subtraction between two vectors results in a vector.

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Can a body move in a curve path without acceleration?

Posted by Meghna Sharma 7 years ago

CBSE > Class 11 > Physics

1 answers

Aashir Arham ⚽?⚽ 7 years ago

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Calculate the rotational kinetic energy of the earth about its own axis (massof the earth=6×10^24kg and radius of earth =6400km)

Posted by Pratheeksha Pkumar 7 years ago

CBSE > Class 11 > Physics

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Why friction is necessary eve

Posted by Pradeep Singh 7 years ago

CBSE > Class 11 > Physics

1 answers

Shivshant Prasad 7 years ago

becoz without friction we cant walk , write on paper and many more things we cant do without friction.. in presence of friction we r able to walk , Run , write etc without it we all will not able to walk properly thats why its necessay and it is evil also becoz to over come friction we need to do work externally and on roads there is wearing and tearing of tyres and due to friction old machine r not able to give their performance best and due to it only nuts of machines also get loose thats why friction is a necessary evil

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Capillarity

Posted by Niraj Toppi 7 years ago

CBSE > Class 11 > Physics

2 answers

Vaibhav Goel 7 years ago

it is a process which takes in liquid due to the prssure differnce acting on different points thats why liquid rises up from one point of material to the another point.

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Shivshant Prasad 7 years ago

it is a process which takes in liquid due to the prssure differnce acting on different points thats why liquid rises up from one point of material to the another point

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Hii Do anyone of u is from BSF school ......if u r a BSFian then please help in finding the previous years question papers of 11

Posted by Abhi Lama 7 years, 1 month ago

CBSE > Class 11 > Physics

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What is Bernoulli's theorem prove it ?

Posted by Saurabh Kumar 7 years, 1 month ago

CBSE > Class 11 > Physics

3 answers

Shivshant Prasad 7 years ago

or we can say sum of pressue head , gravitional head and velocity head is constant provided that there is only one source and sink

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Shivshant Prasad 7 years ago

it states that sum of pressure energy ,kinetic energy and potential energy for a given mass is constant

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Talib Gazi 7 years, 1 month ago

P1>P2 T1>T2 V1>V2

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If 1 kg of water at 100°C is vapourised in open atmosphere. Its internal energy is?

Posted by Panchi Goyal 7 years, 1 month ago

CBSE > Class 11 > Physics

1 answers

Viraj Goenka 7 years, 1 month ago

Not changed... Bcz temp is same (100°C) Nd u will also get 100 marks All the best ..??

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Is refrigerator a heat engine or anythimg else on principle does it works?

Posted by Mehak Rawat 7 years, 1 month ago

CBSE > Class 11 > Physics

1 answers

Shivshant Prasad 7 years, 1 month ago

refrigerator is reverse of heat engine In heat engine heat is used from souce at high temp and remaining heat is rejected to sink at low temp whereas in refrigerator heat is taken from sink at low temp and remaining heat is rejected to source at high temp and in refrigerator we have to supply heat from externally becoz heat cant be supplied from low temp to high temp as proved by second law of thermodynamics by kelvin and clausis statement

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Derive an expression for pressure exerted by an ideal gas on the basis of kinetic theory of gases.

Posted by Iqra Nayab 7 years, 1 month ago

CBSE > Class 11 > Physics