Advertisements
Advertisements
Question
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
Advertisements
Solution
Take the given iron bar AB. Wound several turns of insulated copper wire over the bar. Connect the ends of the wire to a battery through a switch. Press the switch to pass current. After some time, the bar AB becomes a magnet.
The end A of the bar at which the current enters the coil in clock¬wise direction becomes the south pole (S) and the end B of the bar at which the current leaves the coil in anti-clockwise direc¬tion becomes the north pole (N).
APPEARS IN
RELATED QUESTIONS
State three uses of an electromagnet?
State two differences between an electromagnet and a permanent magnet.
State two factors on which the magnitude of an induced e.m.f. in the secondary coils of a transformer depends.
State the purpose of the iron core.
Why is soft iron generally used as the core of the electromagnet?
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
State the factors, on which depends the magnitude of the force acting on current carrying conductor, when it is kept in a magnetic field perpendicular to it.
State and explain Maxwell’s Cork Screw Rule.
(i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.
(ii) Name the law which helped you to find the direction of the magnetic field lines.
