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प्रश्न
How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram.
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उत्तर
The door bell or the electric bell makes use of the principle of an electromagnet. A horseshoe type of electromagnet is used in an electric bell which is connected to the source of current through a switch. It has a metallic gong, a hammer to strike the gong and screw attached to a soft iron strip.
When the button is pressed, the circuit is complete and the hammer gets attracted to the gong thereby striking it to produce a ringing sound.
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संबंधित प्रश्न
An electric bell has an electromagnet.
Fill in the following blank with suitable words:
If a coil is viewed from one end and the current flows in an anticlockwise direction, then this end is a ........... pole.
Fill in the following blank with suitable words:
If a coil is viewed from one end, and the current flows in a clockwise direction, then this end is a ........... pole.
For the coil in the diagram below, when the switch is pressed:
(a) what is the polarity of end A?
(b) which way will the compass point then?
How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?
(c) Considering the relationship in the first pair, complete the second paie :
AgCI : White :: CuI2 : ___________
Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:
(a) the current is passed through the wire.
(b) the current through the wire is increased
(c) the current through the wire is reversed.
Identify the given figure, write the labels of it.
Define the magnetic effect of electric current.
Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.
