1
JEE Main 2020 (Online) 3rd September Evening Slot
+4
-1
A perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field $$\overrightarrow B$$ . Then the field inside the paramagnetic substance is :
A
$$\overrightarrow B$$
B
zero
C
much large than $$\left| {\overrightarrow B } \right|$$ and parallel to $$\overrightarrow B$$
D
much large than $$\left| {\overrightarrow B } \right|$$ but opposite to $$\overrightarrow B$$
2
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
A charged particle carrying charge 1 $$\mu$$C is moving
with velocity $$\left( {2\widehat i + 3\widehat j + 4\widehat k} \right)$$ ms–1. If an external
magnetic field of $$\left( {5\widehat i + 3\widehat j - 6\widehat k} \right)$$× 10–3 T exists in the region where the particle is moving then the
force on the particle is $$\overrightarrow F$$ × 10–9 N. The vector $$\overrightarrow F$$ is :
A
$${ - 0.30\widehat i + 0.32\widehat j - 0.09\widehat k}$$
B
$${ - 300\widehat i + 320\widehat j - 90\widehat k}$$
C
$${ - 30\widehat i + 32\widehat j - 9\widehat k}$$
D
$${ - 3.0\widehat i + 3.2\widehat j - 0.9\widehat k}$$
3
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
An elliptical loop having resistance R, of semi major axis a, and semi minor axis b is placed in magnetic field as shown in the figure. If the loop is rotated about the x-axis with angular frequency $$\omega$$, the average power loss in the loop due to Joule heating is :
A
$${{\pi abB\omega } \over R}$$
B
$${{{\pi ^2}{a^2}{b^2}{B^2}{\omega ^2}} \over R}$$
C
$${{{\pi ^2}{a^2}{b^2}{B^2}{\omega ^2}} \over {2R}}$$
D
Zero
4
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
Magnitude of magnetic field (in SI units) at the centre of a hexagonal shape coil of side 10 cm, 50 turns and carrying current I (Ampere) in units of $${{{\mu _0}I} \over \pi }$$ is :
A
250$$\sqrt 3$$
B
5$$\sqrt 3$$
C
500$$\sqrt 3$$
D
50$$\sqrt 3$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination