Advertisements
Advertisements
प्रश्न
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 ______.
Advertisements
उत्तर
Electric bell magnet - soft iron
APPEARS IN
संबंधित प्रश्न
State two ways of magnetising an iron piece?
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.
How does a magnetic field set up by a solenoid change when number of turns are increased?
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
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.
Point out three differences between an electromagnet and a bar (or permanent) magnet.
(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 word.
How is an electromagnet made?
