| 1. | The initial permeability of an iron rod is ? | |
|
the highest permeability of the iron rod
|
||
|
the lowest permeability of the iron rod
|
||
|
the permeability at the end of the iron rod
|
||
|
the permeability almost in non magnetised state
|
||
View Answer
Discuss in Forum
Report Question| 2. | Magnetism of a magnet can be destroyed by ? | |
|
heating
|
||
|
hammering
|
||
|
by inductive action of another magnet
|
||
|
by all above methods
|
||
| 3. | Temporary magnets are used in ? | |
|
loud-speakers
|
||
|
generators
|
||
|
motors
|
||
|
all of the above
|
||
| 4. | For which of the following materials the saturation value is the highest ? | |
|
Ferromagnetic materials
|
||
|
Paramagnetic materials
|
||
|
Diamagnetic materials
|
||
|
Ferrites
|
||
| 5. | Two long parallel conductors carry 100 A. If the conductors are separated by 20 mm the force per metre of length of each conductor will be ? | |
|
100 N
|
||
|
10 N
|
||
|
1 N
|
||
|
0.1 N
|
||
| 6. | The stray line of magnetic flux is defined as ? | |
|
a line vertical to the flux lines
|
||
|
the mean length of a ring shaped coil
|
||
|
a line of magnetic flux in a non uniform field
|
||
|
a line of magnetic flux which does not follow the designed path
|
||
| 7. | The commonly used material for shielding or screening magnetism is ? | |
|
copper
|
||
|
aluminium
|
||
|
soft iron
|
||
|
brass
|
||
| 8. | Unit for quantity of electricity is ? | |
|
ampere-hour
|
||
|
watt
|
||
|
joule
|
||
|
coulomb
|
||
| 9. | The attraction capacity of electromagnet will increase if the ? | |
|
core length increases
|
||
|
core area increases
|
||
|
flux density decreases
|
||
|
flux density increases
|
||
| 10. | The relative permeability of ...... materials is not constant ? | |
|
diamagnetic
|
||
|
paramagnetic
|
||
|
ferromagnetic
|
||
|
insulating
|
||