Advertisements
Advertisements
प्रश्न
What is an electromagnet? List any two uses.
Advertisements
उत्तर
The magnetic field produced due to the current flowing in a coil or a solenoid can be used to magnetize a material like soft iron temporarily. The insulated copper wire is wrapped on a soft iron piece. When current is passed through the coil using a battery and a key the iron piece behaves like a bar magnet as long as the current is being passed. Such a magnet is called an electromagnet.
Uses of Electromagnet :
1) Magnets are used inside TVs, Sound speakers, and radios.
2) Magnets are used inside a generator to transform mechanical energy to electrical energy
APPEARS IN
संबंधित प्रश्न
A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the loop. What is the emf developed across the cut if the velocity of the loop is 1 cm s−1 in a direction normal to the
- longer side,
- shorter side of the loop?
For how long does the induced voltage last in each case?
What is electromagnetic induction?
When an electric current is passed through any wire, a magnetic field is produced around it. Then why an electric iron connecting cable does not attract nearby iron objects when electric current switched on through it?
Calculate the dimensions of (a) \[\int \overrightarrow{E} . d \overrightarrow{l,}\] (b) vBl and (c) \[\frac{d \Phi_B}{dt}.\] The symbols have their usual meaning.
Figure shows a wire sliding on two parallel, conducting rails placed at a separation l. A magnetic field B exists in a direction perpendicular to the plane of the rails. What force is necessary to keep the wire moving at a constant velocity v?
An electron moves on a straight-line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of the current, if any, induced in the coil?
Show that Lenz’s law is in accordance with the law of conservation of energy.
A cylindrical bar magnet (A) and similar unmagnetized cylindrical iron bar (B) are dropped through metallic pipe. The time taken to come down by ____________.
In the current carrying conductor (AOCDEFG) as shown, the magnetic induction at point O is ______.
(R1 and R2 are radii of CD and EF respectively. l = current in the loop, μ0 = permeability of free space)
