Electromagnet - class-VIII
Description: electromagnet | |
Number of Questions: 16 | |
Created by: Girish Goud | |
Tags: magnetic effects of current and magnetism physics electrical appliances in everyday life electro-magnetism magnetism moving charges and magnetism magnetism and electromagnetism |
A permanent magnet in the shape of a thin cylinder of length $10$cm has magnetisation (M) $=10^6$A $m^{-1}$. It's magnetization current $I _M$ is?
The strength of an electromagnet can be increased by.
For making a strong electromagnet, the material of the core should be
strength of electromagnet increases when
Two electromagnets are made by wrapping a few turns of wire on similar nails and passing the same amount of electric current through them.The number of turn of the wire wrapped over the two iron nails are in the ratio 2:1.The strength of
An example of a perfect diamagnet is a superconductor . This implies that when a superconductor is put in a magnetic field of intensity $B$, the magnetic field ${B _s}$ inside the superconductor will be such that:
One bar magnet and one coil both are in a steady state. North pole of the magnet is towards the coil, then this end of the coil becomes.
The phenomeno of paramagnetism is a consequnce of
Complete the given statement, the strength of an electromagnet can be:
When a magnet is moved with its south pole towards a closed coil, the nearer end of the coil acts like a
Electromagnets are used in
Electromagnets are used in
Electromagnets are used in
In which of the following devices is an electromagnet used?
a. Electric tram
b. Loud speaker
c. Telegraph
d. Relay microphone
Match the following
1. Industrial use | a. Study of magnetic properties under magnetic field |
---|---|
2. Scientific use | b. Removing pieces of iron from wounds |
3. Medical use | c. To separate iron filaments from other waster |
4. Easiest method | d. Lifting and transporting heavy loads of iron mass |
When the current through the electromagnet of a relay reaches a particular value.