The yield point of a typical solid is about 1%. Suppose you are lying horizontally and two persons are pulling your hands and two persons are pulling your legs along your own length. How much will be the increase in your length if the strain is 1% ? Do you think your yield point is 1% or much less than that ?

The total number of electrons in the human body is typically in the order of 10^(28) . Suppose due to some reason you and your friend lost 1% of this number of electrons. Calculate the electrostatic force between you and your friend separated at a distance of 1m. Compare this with your weight . Assume mass of each person is 60 kg and use point charge approximation.

Two large conducting spheres carrying charges Q_1, and Q_2, are brought close to each other. Is the magnitude of electrostatic force between theme exactly given by (Q_1Q_2)/(4pi epsi_(0) r^(2)) , where r is the distance between their centres? b. If Coulomb's law involved 1/r^(3) dependence ("instead of "1/r^2), would Gauss law be still true? c. A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point? d. What is the work done by the field of a nucleus in a complete circular orbit of the electron? What if the orbit is elliptical? e. We know that electric field is discontinuous across the surface of a charged conductor. Is electric potential also discontinuous there? f. What meaning would you give to the capacitance of a single conductor? g. Guess a possible reason why water has a much greater dielectric constant (=80) than say, mica (= 6).

Plot the points A(1,0), B(-7,2),C(-3,7) on a graph sheet and join them to form a triangle. Plot the point G(-3,3). Join AG and extend it to intersect BC at D. Join BG and extend it to intersect AC at E. What do you infer when you measure the distance between BD and DC and the distance between CE and EA? Using distance formula find the lengths of CG and GF, where F in on AB. Write your inference about AG:GD, BG:GE and CG:GF,

A retired person wants to invest an amount upto Rs 20,000. His broker recommends investing in two types of bonds A and B, bond A yielding 10% return on the amount invested and bond B yielding 15% return on the amount invested. After some consideration he decides to invest atleast Rs 5,000 in bond A and not more than Rs 8,000 in bond B. He also wants to invest atleast as much in bond A as in bond B. How should he invest to maximise his return on investment?

In a T20 match, Chennai Super Kings needed just 6 runs to win with 1 ball left to go in the last over. The last ball was bowled and the batsman at the crease hit it high up. The ball traversed along a path in a vertical plane and the equation of the path is y=ax^(2)+bx+c with respect to a xy -coordinate system in the vertical plane and the ball traversed through the points (10,8),(20,16),(40,22), can you conclude that Chennai Super Kings won the match? Justify your answer. (All distances are measured in metres and the meeting point of the plane of the path with the farthest boundary line is (70,0).)

In a T20 match, Chennai Super Kings needed just 6 runs to win with 1 ball left to go in the last over. The last ball was bowled and the batsman at the crease hit it high up. The ball traversed along a path in a vertical plane and the equation of the path is y=ax^(2)+bx+c with respect to a xy-coordinate system in the vertical plane and the ball traversed through the points (10,8),(20,16), (30,18) can you conclude that Chennai Super Kings won the match? Justify your answer. (All distances are measured in metres and the meeting point of the plane of the path with the farthest boundary line is (70,0).

Answer the following questions . a. The earth's magnetic field varies from point is space. Does it also change with time ? It so , on what time scate does it change appreciably ? b. The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism why ? c. The charged currents in the outer conducting regions of the earth's core are thought to be responsible for earth's magnetism . What might be the ' battery ' (i.e., the source of energy) to sustain these currents ? d. The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth's field in such distant past ? e. The earth's field departs from its dipole substantially at large distances (greater than about 30,000 km) what agencies may be responsible for this distortion ? f. Interstellar space has an extremely weak magnetic field of the order of 10^(-12) T, Can such a weak field be of any significant consequence ? Explain. [Note : Exercise 2 is meant mainly to arouse your curiosity . Answers to some question above are tentative or unknown . Brief answers wherever possible are given at the end . For details , you should consult a good text on geomagnetism.]

Plot the following points on a graph sheet by taking the scale as 1cm=1 unit. Find how far the points are from each other? A(1,0) and D(4,0). Find AD and also DA. Is AD=DA? You plot another set of points and verify your Result.