SAI'S SCIENCE AND MATHS CLASSES

Dilation in time that explains the Twin Paradox , Assume out of two twins one entered a  Time Machine which is moving with a velocity of 0.9  c , where " c" is the velocity of light in vacuum then 40 years in the Time Machine corresponds to 92 years on earth ; that is of the twins the time traveler will be younger compare to his twin brother on earth This is Twin Paradox in special theory of relativity .

Relation between horizontal range and maximum height of a Projectile The relation between the range   on the horizontal plane and the maximum height   reached at   is: Proof  ×  (This is originally edited by Saisundar for wiki) For details refer  Wiki pedia

In a meter bridge a resistance of R Ω  and a shunt resistance S Ω are connected as shown, the null point is found to be at 40cm from A If a 12 Ω resistor is connected in parallel with S the null point changes to 50cm Find R and S. 1 st case R / 40=S / 60 R=2S/3 --------------- (1) 2 nd case R / 50= [12S / (12+S)] / 50      (12 Ω and S Ω are connected in parallel )  ie R=12S / (12+S) ---------------(2) solving (1) and (2) S=6 Ω and R=4 Ω

SAI'S SCIENCE AND MATHS CLASSES: Renewable Energy-Solar : The conventional energy sources are depleting at an exponential  rate .The energy crisis is a major concern for the nation around. The c...

The conventional energy sources are depleting at an exponential  rate .The energy crisis is a major concern for the nation around. The coal will last long only for 100 years or less petroleum resource will be exhausted nearly in 50 years time. The oil producing countries it self is moving towards the introduction of renewable energy sources , major among them is Solar energy. The energy production in the sun is  by the  nuclear fusion , hydrogen in the core of sun is converting in to heavier nucleus helium during this process the nuclear binding energy is liberating in the form useful energy . The plants can absorb the visible light and utilize it  for photosynthesis . The use of solar energy by natural means is coming only 1 to 2 % , rest of the energy is un utilized The solar energy capturing technique (Photo Voltaic) was introduced by Charles Fritts   in the year 1883 The solar energy can be  utilized in the following ways 1.  ...

A  10m long wire of 20 ῼ resistance is   used as a potentiometer wire This wire is connected with a 5V battery along an external resistance of 480 ῼ If an unknown emf E is balanced at 600 cm calculate 1) potential gradient 2) the value of E 1)       The total resistance =480+20 = 500 ῼ So the current in the circuit=5/500=1/100 A Potential drop across the wire= 20 × (1/100)=1/5 V . . . Potential Gradient =potential drop per unit length= (1/5) / 10= 1/50 v/m 2)  The unknown emf E= Potential gradient × Balancing length E =(1/50) × 6= 6/50 V

1)  When a steady current flows through a conductor of non uniform cross section which of the quantities remains constant a) Current b) current density c) electric field d) drift speed a) we know that I=Q/ t so current is independent of area of cross section b) current density j = I / A ie current density is inversely proportional to area of cross section c) electric field E = V / l E=IR / l E=(Iρl) /Al E=Iρ / A so E   is inversely proportional to area of cross section d) V d =I / nAe so the drift speed is inversely proportional to area of cross section. 2) The fig shows a plot between  1/ √ V, where V is the accelarating potential Vs de Broglie wave length  λ in the case of two particles having same charge q but different masses m 1 and m 2 with lines A and B which one will have smaller mass λ =h/p =h / ( √ 2mK) λ=h/ ( √ 2mqV) λ=h/ ( √ 2mq) ×(1/  √ V ) (1/  √ V )=( √ 2mq) /h ×  λ slope of the given graph...