question_answer 1)
A very small magnet is placed in the magnetic meridian with its south pole pointing north. The null point is obtained 20 cm away from the centre of the magnet. If the earth's magnetic field (horizontal component) at this point be 0.3 gauss, the magnetic moment of the magnet is [CPMT 1987; MNR 1978]
A)
\[8.0\times {{10}^{2}}e.m.u.\] done
clear
B)
\[1.2\times {{10}^{3}}e.m.u.\] done
clear
C)
\[2.4\times {{10}^{3}}e.m.u.\] done
clear
D)
\[3.6\times {{10}^{3}}e.m.u.\] done
clear
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question_answer 2)
Intensity of magnetic field due to earth at a point inside a hollow steel box is [MP PET 1995]
A)
Less than outside done
clear
B)
More than outside done
clear
C)
Same done
clear
D)
Zero done
clear
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question_answer 3)
Earth's magnetic field always has a horizontal component except at or Horizontal component of earth's magnetic field remains zero at [CPMT 1971, 81, 83]
A)
Equator done
clear
B)
Magnetic poles done
clear
C)
A latitude of 60o done
clear
D)
An altitude of 60o done
clear
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question_answer 4)
A dip needle in a plane perpendicular to magnetic meridian will remain [NCERT 1975; MP PMT 1984; MP PET 1995]
A)
Vertical done
clear
B)
Horizontal done
clear
C)
In any direction done
clear
D)
At an angle of dip to the horizontal done
clear
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question_answer 5)
At magnetic poles of earth, angle of dip is [CPMT 1977, 91; NCERT 1981; MP PET 1997; Pb PET 2002]
A)
Zero done
clear
B)
45o done
clear
C)
90o done
clear
D)
180o done
clear
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question_answer 6)
The correct relation is [CPMT 1986; MP PET 1981; AFMC 1996]
A)
\[B=\frac{{{B}_{V}}}{{{B}_{H}}}\] done
clear
B)
\[B={{B}_{V}}\times {{B}_{H}}\] done
clear
C)
\[|B|=\sqrt{B_{H}^{2}+B_{V}^{2}}\] done
clear
D)
\[B={{B}_{H}}+{{B}_{V}}\] (Where \[{{B}_{H}}=\]Horizontal component of earth's magnetic field; \[{{B}_{V}}\]= Vertical component of earth's magnetic field and B = Total intensity of earth's magnetic field) done
clear
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question_answer 7)
At a certain place, the horizontal component of earth's magnetic field is \[\sqrt{3}\]times the vertical component. The angle of dip at that place is [MP PMT 1984, 85; AFMC 2000]
A)
\[60{}^\circ \] done
clear
B)
\[45{}^\circ \] done
clear
C)
\[90{}^\circ \] done
clear
D)
\[\begin{align} & 2rH \\ & {{\mu }_{0}}N \\ \end{align}\] done
clear
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question_answer 8)
The vertical component of earth's magnetic field is zero at or The earth's magnetic field always has a vertical component except at the [NCERT 1980, 88; CPMT 1983; MP PMT 1996]
A)
Magnetic poles done
clear
B)
Geographical poles done
clear
C)
Every place done
clear
D)
Magnetic equator done
clear
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question_answer 9)
The angle between the magnetic meridian and geographical meridian is called [MNR 1990; UPSEAT 1999, 2000; MP PMT 2000]
A)
Angle of dip done
clear
B)
Angle of declination done
clear
C)
Magnetic moment done
clear
D)
Power of magnetic field done
clear
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question_answer 10)
The lines of forces due to earth's horizontal component of magnetic field are [CPMT 1985; MP PMT 1980; AIIMS 1998]
A)
Parallel straight lines done
clear
B)
Concentric circles done
clear
C)
Elliptical done
clear
D)
Parabolic done
clear
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question_answer 11)
At a place, if the earth's horizontal and vertical components of magnetic fields are equal, then the angle of dip will be [SCRA 1994; DCE 2001; MP PMT 2002]
A)
\[30{}^\circ \] done
clear
B)
\[90{}^\circ \] done
clear
C)
\[45{}^\circ \] done
clear
D)
0° done
clear
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question_answer 12)
If the angles of dip at two places are 30o and 45o respectively, then the ratio of horizontal components of earth's magnetic field at the two places will be [MP PET 1989]
A)
\[\sqrt{3}:\sqrt{2}\] done
clear
B)
\[1:\sqrt{2}\] done
clear
C)
\[1:\sqrt{3}\] done
clear
D)
\[1:2\] done
clear
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question_answer 13)
At a place the earth's horizontal component of magnetic field is \[0.36\times {{10}^{-4}}weber/{{m}^{2}}\]. If the angle of dip at that place is 60o, then the vertical component of earth's field at that place in weber/m2 will be approximately [MP PMT 1985]
A)
\[0.12\times {{10}^{-4}}\] done
clear
B)
\[0.24\times {{10}^{-4}}\] done
clear
C)
\[0.40\times {{10}^{-4}}\] done
clear
D)
\[0.62\times {{10}^{-4}}\] done
clear
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question_answer 14)
The angle of dip at a place is 40.6o and the intensity of the vertical component of the earth's magnetic field \[V=6\times {{10}^{-5}}\]Tesla. The total intensity of the earth's magnetic field (I) at this place is [MP PMT 1993]
A)
\[7\times {{10}^{-5}}tesla\] done
clear
B)
\[6\times {{10}^{-5}}tesla\] done
clear
C)
\[5\times {{10}^{-5}}tesla\] done
clear
D)
\[9.2\times {{10}^{-5}}tesla\] done
clear
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question_answer 15)
The angle of dip is the angle [CPMT 1978]
A)
Between the vertical component of earth's magnetic field and magnetic meridian done
clear
B)
Between the vertical component of earth's magnetic field and geographical meridian done
clear
C)
Between the earth's magnetic field direction and horizontal direction done
clear
D)
Between the magnetic meridian and the geographical meridian done
clear
View Solution play_arrow
question_answer 16)
At a certain place the angle of dip is 30° and the horizontal component of earth's magnetic field is 0.50 Oersted. The earth's total magnetic field is [CPMT 1990]
A)
\[\sqrt{3}\] done
clear
B)
\[1\] done
clear
C)
\[\frac{1}{\sqrt{3}}\] done
clear
D)
\[\frac{1}{2}\] done
clear
View Solution play_arrow
question_answer 17)
The angle of dip at the magnetic equator is [MP PET 1984; MP PMT 1987; CBSE PMT 1989, 90; MP Board 1980; CPMT 1977, 87, 90; Manipal MEE 1995]
A)
0° done
clear
B)
45° done
clear
C)
30° done
clear
D)
90° done
clear
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question_answer 18)
The line on the earth's surface joining the points where the field is horizontal is [MNR 1985; UPSEAT 1999; Pb PET 2004]
A)
Magnetic meridian done
clear
B)
Magnetic axis done
clear
C)
Magnetic line done
clear
D)
Magnetic equator done
clear
E)
(e) Isogonic line done
clear
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question_answer 19)
The angle between the earth's magnetic and the earth's geographical axes is [MNR 1979]
A)
Zero done
clear
B)
17° done
clear
C)
23° done
clear
D)
None of these done
clear
View Solution play_arrow
question_answer 20)
The lines joining the places of the same horizontal intensity are known as [MNR 1984]
A)
Isogonic lines done
clear
B)
Aclinic lines done
clear
C)
Isoclinic lines done
clear
D)
Agonic lines done
clear
E)
(e) Isodynamic lines done
clear
View Solution play_arrow
question_answer 21)
Ratio between total intensity of magnetic field at equator to poles is [IIT 1970; CPMT 1981]
A)
1 : 1 done
clear
B)
1 : 2 done
clear
C)
2 : 1 done
clear
D)
1 : 4 done
clear
View Solution play_arrow
question_answer 22)
A line passing through places having zero value of magnetic dip is called [CPMT 1987]
A)
Isoclinic line done
clear
B)
Agonic line done
clear
C)
Isogonic line done
clear
D)
Aclinic line done
clear
View Solution play_arrow
question_answer 23)
At a place, the horizontal and vertical intensities of earth's magnetic field is 0.30 Gauss and 0.173 Gauss respectively. The angle of dip at this place is [MP PMT 1986]
A)
30° done
clear
B)
90° done
clear
C)
60° done
clear
D)
45° done
clear
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question_answer 24)
The angle of dip at a place is 60°. At this place the total intensity of earth's magnetic field is 0.64 units. The horizontal intensity of earth's magnetic field at this place is [MP PET 1984]
A)
1.28 units done
clear
B)
0.64 units done
clear
C)
0.16 units done
clear
D)
0.32 units done
clear
View Solution play_arrow
question_answer 25)
The magnetic compass is not useful for navigation near the magnetic poles because [BIT Ranchi 1982]
A)
The magnetic field near the poles is zero done
clear
B)
The magnetic field near the poles is almost vertical done
clear
C)
At low temperature, the compass needle looses its magnetic properties done
clear
D)
Neither of the above done
clear
View Solution play_arrow
question_answer 26)
The angle of dip at a place on the earth gives [MP PET 1994]
A)
The horizontal component of the earth's magnetic field done
clear
B)
The location of the geographic meridian done
clear
C)
The vertical component of the earth's field done
clear
D)
The direction of the earth's magnetic field done
clear
View Solution play_arrow
question_answer 27)
At the magnetic north pole of the earth, the value of horizontal component of earth's magnetic field and angle of dip are, respectively [MP PMT 1994]
A)
Zero, maximum done
clear
B)
Maximum, minimum done
clear
C)
Maximum, maximum done
clear
D)
Minimum, minimum done
clear
View Solution play_arrow
question_answer 28)
At a place, the magnitudes of the horizontal component and total intensity of the magnetic field of the earth are 0.3 and 0.6 Oersted respectively. The value of the angle of dip at this place will be [MP PMT 1994]
A)
60° done
clear
B)
45° done
clear
C)
30° done
clear
D)
0° done
clear
View Solution play_arrow
question_answer 29)
A dip circle is at right angle to the magnetic meridian. What will be the apparent dip [AFMC 1995]
A)
0° done
clear
B)
30° done
clear
C)
60º done
clear
D)
90° done
clear
View Solution play_arrow
question_answer 30)
A bar magnet is placed north-south with its north pole due north. The points of zero magnetic field will be in which direction from the centre of the magnet [MNR 1995; MP PMT 1995; UPSEAT 2000]
A)
North and south done
clear
B)
East and west done
clear
C)
North-east and south-west done
clear
D)
North-west and south-east done
clear
View Solution play_arrow
question_answer 31)
In two separate experiments the neutral points due to two small magnets are at a distance of r and 2r in broad side-on position. The ratio of their magnetic moments will be [MP PMT 1985]
A)
4 : 1 done
clear
B)
1 : 2 done
clear
C)
2 : 1 done
clear
D)
1 : 8 done
clear
View Solution play_arrow
question_answer 32)
The magnetic field due to the earth is closely equivalent to that due to [BIT Ranchi 1982]
A)
A large magnet of length equal to the diameter of the earth done
clear
B)
A magnetic dipole placed at the centre of the earth done
clear
C)
A large coil carrying current done
clear
D)
Neither of the above done
clear
View Solution play_arrow
question_answer 33)
The earth's magnetic field at a certain place has a horizontal component 0.3 Gauss and the total strength 0.5 Gauss. The angle of dip is [MP PMT 1995]
A)
\[{{\tan }^{-1}}\frac{3}{4}\] done
clear
B)
\[{{\sin }^{-1}}\frac{3}{4}\] done
clear
C)
\[{{\tan }^{-1}}\frac{4}{3}\] done
clear
D)
\[{{\sin }^{-1}}\frac{3}{5}\] done
clear
View Solution play_arrow
question_answer 34)
The value of the horizontal component of the earth's magnetic field and angle of dip are \[1.8\times {{10}^{-5}}Weber/{{m}^{2}}\] and 30° respectively at some place. The total intensity of earth's magnetic field at that place will be [MP PET 1996]
A)
\[2.08\times {{10}^{-5}}Weber/{{m}^{2}}\] done
clear
B)
\[3.67\times {{10}^{-5}}Weber/{{m}^{2}}\] done
clear
C)
\[3.18\times {{10}^{-5}}Weber/{{m}^{2}}\] done
clear
D)
\[5.0\times {{10}^{-5}}Weber/{{m}^{2}}\] done
clear
View Solution play_arrow
question_answer 35)
When the N-pole of a bar magnet points towards the south and S-pole towards the north, the null points are at the [MP PMT 1996]
A)
Magnetic axis done
clear
B)
Magnetic centre done
clear
C)
Perpendicular divider of magnetic axis done
clear
D)
N and S poles done
clear
View Solution play_arrow
question_answer 36)
Lines which represent places of constant angle of dip are called
A)
Isobaric lines done
clear
B)
Isogonic lines done
clear
C)
Isoclinic lines done
clear
D)
Isodynamic lines done
clear
View Solution play_arrow
question_answer 37)
The vertical component of the earth's magnetic field is zero at a place where the angle of dip is [MP PMT/PET 1998]
A)
0° done
clear
B)
45° done
clear
C)
60° done
clear
D)
90° done
clear
View Solution play_arrow
question_answer 38)
At a certain place, the horizontal component \[{{B}_{0}}\] and the vertical component \[{{V}_{0}}\] of the earth's magnetic field are equal in magnitude. The total intensity at the place will be [MP PMT 1999, 2003]
A)
\[{{B}_{0}}\] done
clear
B)
\[B_{0}^{2}\] done
clear
C)
\[2{{B}_{0}}\] done
clear
D)
\[\sqrt{2}{{B}_{0}}\] done
clear
View Solution play_arrow
question_answer 39)
A compass needle will show which one of the following directions at the earth's magnetic pole [KCET 1993, 94]
A)
Vertical done
clear
B)
No particular direction done
clear
C)
Bent at 45° to the vertical done
clear
D)
Horizontal done
clear
View Solution play_arrow
question_answer 40)
The north pole of the earth's magnet is near the geographical [KCET 1994]
A)
South done
clear
B)
East done
clear
C)
West done
clear
D)
North done
clear
View Solution play_arrow
question_answer 41)
The magnetic field of earth is due to [JIPMER 1997]
A)
Motion and distribution of some material in and outside the earth done
clear
B)
Interaction of cosmic rays with the current of earth done
clear
C)
A magnetic dipole buried at the centre of the earth done
clear
D)
Induction effect of the sun done
clear
View Solution play_arrow
question_answer 42)
A short magnet of moment 6.75 Am2 produces a neutral point on its axis. If horizontal component of earth's magnetic field is \[5\times {{10}^{-5}}Wb/{{m}^{2}}\], then the distance of the neutral point should be [SCRA 1994]
A)
10 cm done
clear
B)
20 cm done
clear
C)
30 cm done
clear
D)
40 cm done
clear
View Solution play_arrow
question_answer 43)
Due to the earth's magnetic field, charged cosmic ray particles [CBSE PMT 1997]
A)
Require greater kinetic energy to reach the equator than the poles done
clear
B)
Require less kinetic energy to reach the equator than the poles done
clear
C)
Can never reach the equator done
clear
D)
Can never reach the poles done
clear
View Solution play_arrow
question_answer 44)
Two bar magnets with magnetic moments 2 M and M are fastened together at right angles to each other at their centres to form a crossed system, which can rotate freely about a vertical axis through the centre. The crossed system sets in earth?s magnetic field with magnet having magnetic moment 2M making and angle q with the magnetic meridian such that [AFMC 1999]
A)
\[\theta ={{\tan }^{-1}}\left( \frac{1}{\sqrt{3}} \right)\] done
clear
B)
\[\theta ={{\tan }^{-1}}\left( \sqrt{3} \right)\] done
clear
C)
\[\theta ={{\tan }^{-1}}\left( \frac{1}{2} \right)\] done
clear
D)
\[\theta ={{\tan }^{-1}}\left( \frac{3}{4} \right)\] done
clear
View Solution play_arrow
question_answer 45)
Angle of dip is 90o at [AIIMS 1999]
A)
Poles done
clear
B)
Equator done
clear
C)
Both (a) and (b) done
clear
D)
None of these done
clear
View Solution play_arrow
question_answer 46)
At a certain place the horizontal component of the earth?s magnetic field is B0 and the angle of dip is 45o. The total intensity of the field at that place will be [MP PET 2000; Pb PET 2003]
A)
B0 done
clear
B)
\[\sqrt{2}\,{{B}_{0}}\] done
clear
C)
2 B0 done
clear
D)
\[B_{0}^{2}\] done
clear
View Solution play_arrow
question_answer 47)
The value of angle of dip is zero at the magnetic equator because on it [MP PET 2001]
A)
V and H are equal done
clear
B)
The value of V and H is zero done
clear
C)
The value of V is zero done
clear
D)
The value of H is zero done
clear
View Solution play_arrow
question_answer 48)
Which of the following relation is correct in magnetism [KCET (Engg./Med.) 2001]
A)
\[{{I}^{2}}={{V}^{2}}+{{H}^{2}}\] done
clear
B)
\[I=V+H\] done
clear
C)
\[V={{I}^{2}}+{{H}^{2}}\] done
clear
D)
\[{{V}^{2}}=I+H\] done
clear
View Solution play_arrow
question_answer 49)
The direction of the null points is on the equatorial line of a bar magnet, when the north pole of the magnet is pointing [AFMC 1999; Pb. PMT 2000; CPMT 2001; MH CET 2003]
A)
North done
clear
B)
South done
clear
C)
East done
clear
D)
West done
clear
View Solution play_arrow
question_answer 50)
Magnetic meridian is a [Orissa JEE 2002]
A)
Point done
clear
B)
Horizontal plane done
clear
C)
Vertical plane done
clear
D)
Line along N-S done
clear
View Solution play_arrow
question_answer 51)
The angle of dip at a certain place is 30o. If the horizontal component of the earth?s magnetic field is H, the intensity of the total magnetic field is [UPSEAT 1993, 2000; MP PMT 2002]
A)
\[\frac{H}{2}\] done
clear
B)
\[\frac{2H}{\sqrt{3}}\] done
clear
C)
\[H\sqrt{2}\] done
clear
D)
\[H\sqrt{3}\] done
clear
View Solution play_arrow
question_answer 52)
The horizontal component of the earth's magnetic field is 0.22 Gauss and total magnetic field is 0.4 Gauss. The angle of dip. is [MP PMT 2004]
A)
\[{{\tan }^{-1}}\,(1)\] done
clear
B)
\[{{\tan }^{-1\,}}(\infty )\] done
clear
C)
\[{{\tan }^{-1\,}}(1.518)\] done
clear
D)
\[{{\tan }^{-1\,}}(\pi )\] done
clear
View Solution play_arrow
question_answer 53)
A bar magnet is situated on a table along east-west direction in the magnetic field of earth. The number of neutral points, where the magnetic field is zero, are [MP PMT 2004]
A)
2 done
clear
B)
0 done
clear
C)
1 done
clear
D)
4 done
clear
View Solution play_arrow
question_answer 54)
At which place, earth's magnetism become horizontal [AFMC 2004]
A)
Magnetic pole done
clear
B)
Geographical pole done
clear
C)
Magnetic meridian done
clear
D)
Magnetic equator done
clear
View Solution play_arrow
question_answer 55)
Isogonic lines on magnetic map will have [AFMC 2004]
A)
Zero angle of dip done
clear
B)
Zero angle of declination done
clear
C)
Same angle of declination done
clear
D)
Same angle of dip done
clear
View Solution play_arrow
question_answer 56)
A current carrying coil is placed with its axis perpendicular to N-S direction. Let horizontal component of earth's magnetic field be Ho and magnetic field inside the loop is H. If a magnet is suspended inside the loop, it makes angle \[\theta \] with H. Then \[\theta \]= [Orissa PMT 2004]
A)
\[{{\tan }^{-1}}\left( \frac{{{H}_{0}}}{H} \right)\] done
clear
B)
\[{{\tan }^{-1}}\left( \frac{H}{{{H}_{0}}} \right)\] done
clear
C)
\[\cos e{{c}^{-1}}\left( \frac{H}{{{H}_{0}}} \right)\] done
clear
D)
\[{{\cot }^{-1}}\left( \frac{{{H}_{0}}}{H} \right)\] done
clear
View Solution play_arrow
question_answer 57)
Let V and H be the vertical and horizontal components of earth's magnetic field at any point on earth. Near the north pole [UPSEAT 2004]
A)
\[V>>H\] done
clear
B)
\[V<<H\] done
clear
C)
\[V=H\] done
clear
D)
\[V=H=0\] done
clear
View Solution play_arrow
question_answer 58)
At the magnetic poles of the earth, a compass needle will be [DCE 2003]
A)
Vertical done
clear
B)
Bent slightly done
clear
C)
Horizontal done
clear
D)
Inclined at 45o to the horizontal done
clear
View Solution play_arrow
question_answer 59)
If magnetic lines of force are drawn by keeping magnet vertical, then number of neutral points will be [MP PMT 1985; CPMT 1985]
A)
One done
clear
B)
Two done
clear
C)
Four done
clear
D)
Five done
clear
View Solution play_arrow