1
JEE Main 2020 (Online) 2nd September Morning Slot
+4
-1
Out of Syllabus
Magnetic materials used for making permanent magnets (P) and magnets in a transformer (T) have different properties of the following, which property best matches for the type of magnet required?
A
T : Large retentivity, small coercivity
B
P : Large retentivity, large coercivity
C
P : Small retentivity, large coercivity
D
T : Large retentivity, large coercivity
2
JEE Main 2020 (Online) 7th January Evening Slot
+4
-1
Out of Syllabus
The figure gives experimentally measured B vs H variation in a ferromagnetic material. The retentivity, coercivity and saturation, respectively, of the material are :
A
1.0 T, 50A/m and 1.5 T
B
1.5 T, 50 A/m and 1.0 T
C
1.5 T, 50 A/m and 2.0 T
D
150 A/m, 1.0 T and 1.5 T
3
JEE Main 2019 (Online) 12th April Morning Slot
+4
-1
Out of Syllabus
A magnetic compass needle oscillates 30 times per minute at a place where the dip is 45o, and 40 times per minute where the dip is 30o. If B1 and B2 are respectively the total magnetic field due to the earth at the two places, then the ratio $${{{B_1}} \over {{B_2}}}$$ is best given by :
A
1.8
B
2.2
C
0.7
D
3.6
4
JEE Main 2019 (Online) 8th April Evening Slot
+4
-1
Two magnetic dipoles X and Y are placed at a separation d, with their axes perpendicular to each other. The dipole moment of Y is twice that of X. A particle of charge q is passing, through their midpoint P, at angle q = 45° with the horizontal line, as shown in figure. What would be the magnitude of force on the particle at that instant ?
(d is much larger than the dimensions of the dipole)
A
$$\left( {{{{\mu _0}} \over {4\pi }}} \right){2M \over {{{\left( {d/2} \right)}^3}}} \times qv$$
B
$$\left( {{{{\mu _0}} \over {4\pi }}} \right){M \over {{{\left( {d/2} \right)}^3}}} \times qv$$
C
$$\sqrt 2 \left( {{{{\mu _0}} \over {4\pi }}} \right){M \over {{{\left( {d/2} \right)}^3}}} \times qv$$
D
0
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