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प्रश्न
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
Name any three appliances based on the magnetic effect of electric current.
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उत्तर
Ammeter, microphone, electric bell, galvanometer, loud speaker, electric generator, electric motor, telephone receiver, radio, stereo speaker.
संबंधित प्रश्न
Will the compass needle show deflection when the switch in the circuit shown by figure is closed?
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
Name the scientist who discovered the magnetic effect of current.
The magnetic effect of current was discovered by:
(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday
Name one device which works on the magnetic effect of current.
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?
In the Activity shown below, how do we think the displacement of rod AB will be affected if
- current in rod AB is increased
- a stronger horse-shoe magnet is used
- length of the rod AB is increased?
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(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
Identify the given figure, write the labels of it.
Explain the magnetic field created around a straight current carrying conductor with the help of a diagram.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
What is that instrument which can detect the presence of electric current in a circuit?
A magnetic compass shows a deflection when placed near a current carrying wire. How will the deflection of the compass get affected if the current in the wire is increased? Support your answer with a reason.
Unscramble the following words:
HTRCO
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:
- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminium rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions:
- Why does the rod get displaced on passing current through it?
- State the rule that determines the direction of the force on the conductor AB.
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- If the U-shaped magnet is held vertically and the aluminium rod is suspended horizontally with its end B towards due north, then on passing current through the rod from B to A as shown, in which direction will the rod be displaced?
- Name any two devices that use current carrying conductors and magnetic fields.
OR
Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
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.
