Advertisements
Advertisements
प्रश्न
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
Advertisements
उत्तर
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
संबंधित प्रश्न
Name and state the rule by which polarity at the ends of a current carrying solenoid is determined.
Name the material of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electric bell ______.
Answer the following in short.
Name a few common appliances that use electromagnets.
State the condition when an electric charge can give rise to a magnetic field.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
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.
How does a magnetic field set up by a solenoid change when cross-sectional area of solenoid is increased?
Write the answer in your words.
How is an electromagnet made?
