Question

29. (a) Describe an activity to
demonstrate the pattern of magnetic
field lines around a straight
conductor carrying current. (b) State
the rule to find the direction of
magnetic field associated with a
current carrying conductor. (c) What
is the shape of a current carrying
conductor whose magnetic
field pattern resembles that of a bar-
magnet?
​

Answer 1

Answer:

(a) Aim: To study the magnetic field due to a straight current-carrying conductor. Apparatus Required: A thick conducting wire, battery, rheostat, magnetic needle, ammeter (0-5 A), key, a cardboard, a stand to hold the wire, iron filings and sprinkler of iron filings.

Procedure: Attach the thick wireSolenoid is the shape of a current-carrying conductor whose magnetic field pattern resembles that of a bar magnet. through a hole at the middle of the cardboard and clamp it in a stand. Attach the ends of the wire through a key, variable resistor and an ammeter. on either side of a battery and hold it vertically and perpendicularly to the board. Spread the iron filings uniformly on the cardboard and place the magnetic needle on the board. Close the key and tap the cardboard slightly and observe the orientation of iron filings. Magnetic field around a straight conducting wired concentric circles indicate the field lines

Observation: Just on closing the key, the iron filings are aligned in the pattern of concentric circles around the wire.

Conclusion: A current-carrying conductor is a source of magnetic field. The magnetic field is in the form of concentric circles whose centre lies on the wire.

(b) It states that if you holding the current-carrying conductor in your right hand such that the thumb points in direction of the current, then the direction in which the fingers encircle, gives the direction of magnetic lines. This rule is also called Maxwell's Corkscrew Rule.

(c) Solenoid is the shape of a current-carrying conductor whose magnetic field pattern resembles that of a bar magnet.

Hope it helps you...