10th Class Science Magnetic Effects of Electric Current Domestic Circuit

        Domestic Circuit

We receives electric supply in our home from the main power supply through cables or poles. It consists of two wires, one with red insulation called live wire and other with black insulation called neutral wire. The potential difference between two wires is 220 volt. These two wires are connected into our homes via meter board through main switch, which consists of safety devices called fuse. From there it is connected to the different switch through the wiring in our house, which are connected in parallel. Often we use two different circuit one with 15 A current used for appliances with higher power rating such as air coolers, geysers etc and other circuit is of 5 A current rating for bulbs, fans, TV etc. There is a third wire with green insulation called earthing and is usually connected to a metal plate deep in the earth, near the house. It acts as a safety device for those appliances having metallic body as it provides low resistance conducting path for the current and prevent any short of leakage of current to the metallic body of the appliance and keeps its potential to that of the earth and prevent any severe electric shock. Thus, electric fuse and earthing are the two safety device used in electric circuit.

      The magnetic field pattern given in the figure below is due to which one of the following?

(a) Straight Conductor                                  

(b) Circular Loop

(c) Solenoid                                                       

(d) Ring

Answer: (c)

       Which types of material is used in the core of electromagnet?

(a) Soft Iron                                                       

(b) Steel

(c) Alloy                                                               

(d) Non Metals

Answer: (a)

          Which one of the following is the correct statement for the magnetic field near the straight conductor?

(a) The field consists of straight lines parallel to the wire

(b) Field consists of radial lines starting from the wire

(c) The field consists of concentric circles with centre on the wire

(d) The field consists of straight lines perpendicular to the wire

(e) None of these

Answer: (c)

           Which one of the following is not used in DC generator?

(a) Coil                                                                 

(b) Brush

(c) Slip Ring                                                        

(d) Magnet                                        

(e) None of these

Answer: (c)

• The magnetic field made by The Earth is so big and strong, that it stretches out into space.
• Hammering and heating a piece of steel or iron in a north to south direction can magnetize it.
• The first primitive testimonies on magnetite came from Peter Peregrinus in 1269.

• Magnetic compass is a device which can be used find the magnetic field direction.
• Magnetic effect produced by electric current is called electromagnetism.
• If we break a bar magnet into two parts, each parts will behave like a independent magnet.
• Like poles repels each other and unlike pole attract each other.
• Magnetic line of forces do not intersect each other.
• An electric motors is a device which convert electrical energy into mechanical energy.
• An electric generator is a device which convert machenical energy into electrical energy.
• Earthing, fuse and main switch are the three main saftey devices in the house hold circuit.