Advertisements
Advertisements
प्रश्न
How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
What device reverses the current?
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the N-pole is removed?
Read the given passage and answer the following questions:
The home electrical connection consists of ‘live’, ‘neutral’ and ‘earth’ wires. The ‘live’ and the ‘neutral’ wires have potential difference of 220 V. The ‘earth’ is connected to ground. Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives a way the two wires come in contact with each other and a large current flows through it producing heat. If any inflammable material (such as wood, cloth, plastic, etc.) exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measure.
- Name the two wires having potential difference of 220 V.
- What is a short circuit?
- Write the function of a fuse.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
______ cells cannot be recharged after use.
An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.
Using an electromagnet, you can make a working model of a railway signal as shown in figure.
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.
