Rahul wants to make an electric circuit.He has a bulb, two wires, a safety pin and a piece of copper. He does not have any electric cell or battery.Suddenly he gets some idea. He uses a lemon instead of a battery and makes a circuit.Will the bulb glow?

A king ordered his Goldsmith to make a crown which should be of pure gold. SO the goldsmith to made a crown of pure gold & brought it to king. but the king was not contended with the crown as he suspected whether it is made of pure gold or not. So he called for Archimedes and asked him to check whether it is a pure gold crowm. Archimedes was serious about this and went his home thinking how to solve this issue. He wanted to take bath, all of a sudden the jumped on to the bath tyb. Water inside the tub had splashed out of it. An idea striked him suddenly he went running naked straight from his bathroom to the king's pace shouting Eureka Eureka on the road side. From this what do we infer ? How Archimeded would have solved this problem ?

a. The top of the atmosphere is at about 400 kV with respectto the surface of the earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth, the field is about 100 Vm^(-1). Why then do we not get a electric shock as we step out of our house into the openy (Assume the house to be a steel cage so there is no field inside!) b. A man fixes outside his house one evening a two metre high insulating slab carrying on its top a large aluminium sheet of area 1m^(2) . Will he get an electric shock if he touches the metal sheet next morning? c. The discharging current in the atmosphere due to the small conductivity of air is known to be 1800A on an average over the globe. Why then does the atmosphere not discharge itself completely in due course and become electrically neutral? In other words, what keeps the atmosphere charged? d. What are the forms of energy into which the electrical energy of the atmosphere is dissipated during a lightning? (Hint: The earth has an electric field of about 100 Vm^(-1) at its surface in the downward direction, corresponding to a surface charge density =-10^(-9) Cm^(-2) ?.