8/6/2019 magetism ques ans...
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2. The magnetic field lines come closer to the each other near
the poles of magnet but they arewidely separated at other
places.
3. The magnetic filed lines do not intersect or cross each
other.Q2. To trace the magnetic field pattern of the bar magnet
1. Sprinkle iron fillings around the magnet and iron filings
will get aligned to show the magneticfield pattern of magnet.
2. Placing the magnetic compass at different positions around
the magnet and using thedeflection of compass needle to get the
magnetic filed pattern around a magnet.
Q 3. The strength of magnetic field is indicated by the degree
of closeness of the field lines. Where the fieldlines are closest
together, the magnetic field is the strongest.
Q 4. The given statement is false because the axis of earths
imaginary magnet and geographical axis of
earth are inclined to each other at an angle of 15.
Q 5. The tip of the compass needlealways points towards the
north pole of the earth and its tail points
towards the south pole of the earth. When the compass is placed
in the magnetic field due to the bar
magnet, then the magnetic force is exerted by the bar magnet on
the compass needle which is itself a tiny
pivoted magnet, due to this magnetic force the needle gets
deflected.
Q 6. Manufacturers use the magnetic strip in the doors of
refrigerators so that the magnetic force of
attraction remain the doors closed to provide the isolation to
the food placed inside it and do not allow the
micro organisms and oxygen to come in contact with them.
Q 7. (a) north, south (b) bar, southQ 8. Refer diagrams
Q 9. The space surrounding the magnet in which the magnetic
force is exerted is called a magnetic field.
The direction of the magnetic field at a point is the direction
of the resultant force acting on a hypothetical
north pole placed at that point. The north end of the compass
needle also indicates the direction of
magnetic field at any point where it is placed.
Q 10. This is a fact that the resultant force on a north pole
can only be in one direction. If the two magnetic
lines will intersect one another then the resultant force on the
north pole at that point will be in two
directions which is not possible.
Q 11. Because the strength of the magnetic field produced is
very weak.
Q 12. (a) the magnetic lines are the lines drawn in a magnetic
field along which a north magnetic pole
would move.
For diagram consult some important diagrams.
(b) due to the current flowing in the liquid core at the centre
of the earth, the earth behaves like a bar
magnet. The direction of the earth magnetic filed resembles that
of imaginary bar magnet of length one
fifth of the diameter of earth buried under its centre. The
north pole of tis imaginary magnet is towards the
geographical south pole and south pole of this imaginary bar
magnet is to wards the geographical north
pole. Due to this magnetic field of the earth a freely suspended
magnet always point towards the noirthand south pole of earth.
Q13. (d) Q 14. (c) Q 15. (c) Q 16. (c) Q 17. (a) Q 18. (b) Q 19.
(d)
Q20. (d) Q21. (c) Q22. (b) Q23. (c)
Q24. Q25. (a) (b) X is the north pole.
Q26. A = N, B = N, C = S, D = S, E = N, F = S
