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प्रश्न
Explain the magnetic field created around a straight current carrying conductor with the help of a diagram.
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उत्तर
- Consider a circuit connected as shown in the figure.
- A cardboard is placed around a thick copper wire. A magnetic needle is used to check the magnetic field around the wire.
- When a large current flows through the thick wire, the magnetic needle shows deflection. At different points on the cardboard, the needle points in different directions.
- When joined the directions shown by the needle, the lines formed indicate that the magnetic field produced around a current-carrying conductor is in the form of concentric circles.
- The deflection in the needle changes according to the current in the conductor. For a given current, if we move the compass needle away from the wire, its deflection decreases.
- The direction of the magnetic field formed around the conductor depends on the direction of the current and is given by the right-hand thumb rule.
- If the thumb of the right hand indicates the direction of the current then, the curled fingers indicate the direction of the magnetic field formed.
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संबंधित प्रश्न
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
The magnetic effect of current was discovered by:
(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday
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?
The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:
What is the polarity of end X?
What is the polarity of end Y?
Name and state the rule which you have used to determine the polarities.
If fuse of 250 mA, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?
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 : ___________
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
Draw a neat labelled diagram to show the magnetic effect of electric current.
Magnetic effect of current was discovered by ______.
Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel at the night to get dim light. Has she taken the right step? Give one reason to justify your answer.
______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
What do you mean by the magnetic effect?
Define the magnetic effect of electric current.
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.
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.
