pls help me my dear friends ques 30 and 31 all parts
Answers
30.A lightning rod ( or lightning conductor is a rod mounted on a structure and intended to protect the structure from a strike. If lightning hits the structure, it will preferentially strike the rod and be conducted to ground through a wire, instead of passing through the structure, where it could start a fire or cause . Lightning rods are also called , air terminals or strike termination devices.
In a lightning protection system, a lightning rod is a single component of the system. The lightning rod requires a connection to earth to perform its protective function. Lightning rods come in many different forms, including hollow, solid, pointed, rounded, flat strips or even bristle brush-like. The main attribute common to all lightning rods is that they are all made of conductive materials, such as and . Copper and its are the most common materials used in lightning protection.
31. a)Magnetic effects of current refers to generation of magnetic field due to current carrying conductor.
b) activity to demonstrate magnetic effects of current.
Materials required :
wire, rectangular cardboard, battery , variable resistance, switch and magnetic compass.
Procedure:
1. Make a whole in the rectangular.
2. Put the wire inside it and fix it with adhesive glue.
3. Connet both ends of the wire to battery and switch on to allow current to flow through the circuit.
4. Bring a magnetic compass near the current carrying wire.
Observation:
We see deflection in magnetic compass needle.
Conclusion:
Since, magnetic compass itself is a Small bar magnet.So, it's deflection shows presence of Magnetic field around the current carrying conductor.
