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Johannes Kepler, , Higher Secondary First year, Physics Learning Material, (Minimum Material to Pass Only), (2019-2020), Prepared by, , S.Jayachandran, P.G.Asst(Physics), GHSS,Manali,Thiruvallur Dt, Chennai-600 068., (9840430109), , Best of Luck for Success, , ஊக்கமது ககவிடேல்
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1.State and prove Bernoullis’s Theorem, Sum of pressure energy, kinetic energy, and, potential energy per unit mass remains constant, for an incompressible, non-viscous fluid in a, streamlined flow., , 3.Obtain the expression for the frequency of a, vibrating string. frequency depends upon applied, force (F) ,length (l),mass per unit length (m), , V is the volume of the liquid entering and, leaving Pipe AB per second. aA, vA and PA be the area, of cross section of the tube, velocity of the liquid and, pressure exerted by the liquid at A respectively., , 4.Derive Poiseuille’s formula for the volume of a, liquid flowing per second through a pipe under, streamlined flow, Volume (v) of the liquid flowing per second, through a capillary tube. depends on coefficient of, viscosity (η) radius of the tube (r), and the, pressure gradient P/l., , From the law of conservation of energy, , 5.Convert 76 cm of mercury pressure into Nm−2, using the method of dimensions., , Dividing by m and writing in general, , 2.Obtain the expression for the force acting on a, body moving in a circular path by dimensional, analysis method. force F depends on mass (m),, velocity (v) and radius (r)., , 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 1
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6.Explain in detail the triangle law of addition., , Two vectors (A & B)are taken as two adjacent, sides of a triangle in the same order. Third side, of the triangle taken in reverse order gives the, resultant (R)of two vectors., , 9.State the law of conservation of total linear, momentum, If no external force act on a system, then the total, linear momentum of the system is constant., , 10.Write the postulates of kinetic theory of gases, 1. All gas molecules are elastic spheres., 2. Molecules of different gases are different., 3. All gas molecules are moving., 4. While moving, gas molecules collide with one, another and wall of container., 5. Collisions are perfectly elastic collision., 6. Collisions are instantaneous(Short Time), Gas molecules obey Newton’s laws of motion, , Angle between Vector, A and Resultant R is, , 11.State and Prove Parallel axis theorem, , 7.Differentiate Scalar Product and Vector product of, two vectors, , 8.Derive the kinematic equations of motion for, constant acceleration (Uniform motion)., , 12.Derive an expression for escape speed, Speed given to an object vertically up so, that it escapes the Earth’s gravity and would never, come back to earth is called Escape speed., , By law of energy conservation, , 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 2
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13.Explain the variation of g with altitude., An object of mass m is at a height h from the surface, of the Earth., , By First law of Thermodynamics, , 14.Explain the variation of g with depth., An object of mass m is at a depth d from the surface, of the Earth, , 17.Explain in detail Newton’s law of cooling., Rate of loss of heat from a body is proportional to, temperature difference between body (T) and, sourroundings (Ts)., , 15.Describe Newton’s formula for velocity of sound, waves in air and also discuss the Laplace’s correction., By Newton,Sound travels as longitudinal wave in air, obeying Isothermal process., , -, , 18.State and explain work energy principle., Total work done on a body by a force is, equal to change in Kinetic Energy of a body., m is the mass,u is the initial velocity,v is the final, velocity,F is the constant force, a is the, acceleration and S is the displacement., , By Laplace,Sound travels as longitudinal wave in air, obeying Adiabatic process., , 16.Derive Mayer’s relation for an ideal gas., μ mole of an ideal gas is taken in a container, with volume V, pressure P and temperature T., Gas is heated at constant volume so that change in, temperature is dT and No Work is done., , Work is equal to change in Kinetic energy., 19.Discuss in detail the energy in simple harmonic, motion., , Gas is heated by giving heat Q at constant Pressure so, that change in temperature is dT and Work done is, dW., 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 3
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Expression for Potential Energy, , 3.1.Difference between, Conservative Force, , Conservative, , and, , Non, , 20. Arrive at an expression for Inelastic collision in, one dimension and discuss various cases., Two masses m1 and m2 move with initial, velocities u1 and u2 before collision. After perfect, inelastic collision both the objects move with a, common velocity v., , 21.Using free body diagram, show that it is easy to, pull an object than to push it., For Pushing, , For Pulling, , Normal pulling force is less than Normal Pushing, Force.So it is easier to Pull than Push., , 3.2.What are the Laws of transverse vibrations in, stretched strings, , 1. Frequency of transverse vibration in strings, varies inversely with the vibrating length., 2. frequency varies directly with the square root of, the tension T,, 3. frequency varies inversely with the square root, of the mass per unit length μ., 3.3.What are the applications of Dimensional, Analysis., Dimensional Analysis is used to, 1) Convert a physical quantity from one system of, units to another., 2) Check whether a physical equation is, dimensionally correct., 3) To derive relations between various physical, quantities., 3.4.What are the Limitations of Dimensional, Analysis., 1) No information about the dimensionless, constants π,e, etc., 2) Physical quantity is a vector or a scalar cannot, be found., 3) Trigonometric,exponential and logarithmic, functions cannot be applied., 4) Equation involving more than three physical, quantities cannot be applied., 5) It can only check on whether a physical relation is, dimensionally correct but not exactly correct., 3.5How will you measure the height of an object, using triangulation method., h is the height of object AB to be measured, , BC =, , x,, , 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 4
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3.6.How will you use radar method to measure larger, distance of a planet., , t is the time interval between, the sending and receiving, the radio waves., , 3.7.How will you measure the distance of the Moon, using parallax method?, AB is the diameter of earth., C is the centre of earth., M is the moon. S1 & S2 are the stars., Ɵ1 is parallax angle between, moon and star S1., Ɵ2 is parallax angle between, moon and star S2., , When the string tied to stone is cut off, the, stone cannot move in circular path due to inertia of, Direction., 3.11.State Kepler’s three laws., Kepler’s first law: All planets revolve around the Sun, in elliptical orbits with the Sun at one of the foci., Kepler’s second law: The radial vector line joining, the Sun and planet sweeps equal areas in equal, intervals of time., Kepler’s third law: The ratio of the square of the, time period of planet to the cubic power of semi, major axis is constant for all the planets., 3.12.What are geostationary and polar satellites?, , 2.1 State Lami’s Theorem, 3.8Write the differences between Static and Kinetic, Friction, , 3.9.State Newton’s Laws, First Law : When there is no net external force, the, body will remain in the same state of rest or, uniform motion., Second Law: Force is equal to rate of change in, momentum, Third Law: For every action, there is equal and, opposite reaction., 3.10.Write the types of Inertia with examples, Inertia of Rest: Inability of an object to change its, state of rest is called inertia of rest., When a bus suddenly starts from rest,, passengers move backwards due to inertia of rest., Inertia of Motion: Inability of an object to change, its state of Motion is called inertia of Motion., When a bus suddenly stops from moving,, passengers move forwards due to inertia of Motion., Inertia of Direction: Inability of an object to change, its state of direction is called inertia of Direction., , If three concurrent forces act on a body, in, equilibrium, then each force is proportional to sine, of the angle between the other two forces., , 2.2Under what condition will a car skid on a, leveled circular road?, If the static friction is less than required, centripetal force to turn, the vehicle will start to, skid., 2.3.Give some examples of Projectile, 1) A bullet fired from a rifle., 2) A ball thrown in any direction., 3) A javelin or shot put thrown by an athlete., 2.4.State Newton’s Universal law of gravitation., Gravitational force between two masses is, directly proportional to product of masses and, inversely proportional to square of the distance, between the masses., 2.5.Will the angular momentum of a planet be, conserved? Justify your answer., Torque experienced by a Planet due to the, gravitational force of the Sun is zero. So angular, momentum of a planet is constant., 2.6. Why is there no lunar eclipse and solar eclipse, every month?, Moon’s orbit is tilted 5° with respect to Earth’s, orbit. Due to 5° tilt, the Sun, Earth and Moon come, in straight line once in some years, depending on the, alignment., , 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 5
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2.7.How seasons occur, Seasons in the Earth arise due to the, rotation of Earth around the Sun with 23.5° tilt., 2.8Which is more elastic, steel or rubber? Why?, Steel produces less strain than rubber for, equal stress. Young’s modulus is higher for steel, than rubber. The object which has higher young’s, modulus is more elastic. So, Steel is more elastic, than rubber, 2.9 State Archimedes principle., A immersed body in liquid experiences, upward thrust equal to weight of liquid displaced, by it., 2.10State the law of floatation, The weight of body is equal to weight of the, liquid displaced by the immersed part of the body., 2.11State Hooke’s law, Stress and Strain are proportional to each, other, for small deformation., 2.12 Why two holes are made to empty an oil tin?, When Oil comes from One hole, Pressure, inside the tin Decreases and oil will not come out., So to increase the air pressure, two holes are made., 2.13Why the passengers are advised to remove the ink, from their pens while going up in an aeroplane?, During flying at a greater height,, Atmospheric pressure decreases. Pressure inside, the ink pen is greater than atmospheric pressure, which will push ink out and cause damage., 2.14We use straw to suck soft drinks, why?, When we suck, the pressure inside, the straw decreases than the atmospheric pressure,, and the soft drink rises in the straw., 2.15 State Weins Displacement law, wavelength of black body radiation with, maximum intensity is inversely proportional to the, absolute temperature of the black body., 2.16State First law of thermodynamics, Change in internal energy (ΔU) is equal to, heat supplied (Q) minus the work done by the, system (W)., 2.17 Why Moon has no atmosphere., Due to low gravity, speed of gas molecules in, moon is greater than escape speed of moon. So all, gases escape., 2.18Define Degrees of freedom, Minimum number of coordinates needed to, specify position and configuration of a thermo, dynamical system in space., , 2.19State law of equipartition of energy., Average kinetic energy of system in thermal, equilibrium is shared by all degrees of freedom., 2.20What is meant by mean free path, Average distance travelled by the molecule, between collisions is called mean free path., 2.21Why Soliders are not allowed to march on a, bridge., Due to Resonance,bridge will collapse., Frequency of the bridge may be equal to, Frequency of stepping on the ground by marching, soldiers., 2.22When a tree is cut, the cut is made on the side, facing the direction tree is required to fall. Why?, While Cutting, Tree is not acted by normal, force. Only Gravitational force acts. Centre of, gravity and mass switches to that side., 2.23 Why does a porter bend forward while carrying a, sack of rice on his back?, By Bending, porter increases area of, Contact, and decreases pressure given by the sack., Centre of gravity moves downwards and stability, increases., 2.24 When walking on ice one should take short steps., Why?, By taking short steps, Lesser force is applied, and normal force and friction force increases.So, we won’t fall., 2.25 Why it is not possible to push a car from inside?, Internal forces of a system(Car) cannot, produce acceleration of a car., 2.26 Why does a parachute descend slowly?, Area of parachute is large. So upward air, resistance is large. So, parachute descend slowly., , ******Dear Students, Learn, write, and practice all answers in this Six, pages several times, to get Pass, Marks*****, , 11 EM To PASS Material S.Jayachandran, PG.Asst,GHSS,Manali,Thiruvallur Dt,, , 9840430109, , Page 6