1
JEE Main 2022 (Online) 26th June Morning Shift
+4
-1

The magnetic flux through a coil perpendicular to its plane is varying according to the relation $$\phi = (5{t^3} + 4{t^2} + 2t - 5)$$ Weber. If the resistance of the coil is 5 ohm, then the induced current through the coil at t = 2 s will be,

A
15.6 A
B
16.6 A
C
17.6 A
D
18.6 A
2
JEE Main 2021 (Online) 1st September Evening Shift
+4
-1
A square loop of side 20 cm and resistance 1$$\Omega$$ is moved towards right with a constant speed v0. The right arm of the loop is in a uniform magnetic field of 5T. The field is perpendicular to the plane of the loop and is going into it. The loop is connected to a network of resistors each of value 4$$\Omega$$. What should be the value of v0 so that a steady current of 2 mA flows in the loop?

A
1 m/s
B
1 cm/s
C
102 m/s
D
10$$-$$2 cm/s
3
JEE Main 2021 (Online) 31st August Evening Shift
+4
-1
A coil is placed in a magnetic field $$\overrightarrow B$$ as shown below :

A current is induced in the coil because $$\overrightarrow B$$ is :
A
Outward and decreasing with time
B
Parallel to the plane of coil and decreasing with time
C
Outward and increasing with time
D
Parallel to the plane of coil and increasing with time
4
JEE Main 2021 (Online) 31st August Morning Shift
+4
-1
A small square loop of side 'a' and one turn is placed inside a larger square loop of side b and one turn (b >> a). The two loops are coplanar with their centres coinciding. If a current I is passed in the square loop of side 'b', then the coefficient of mutual inductance between the two loops is :
A
$${{{\mu _0}} \over {4\pi }}8\sqrt 2 {{{a^2}} \over b}$$
B
$${{{\mu _0}} \over {4\pi }}{{8\sqrt 2 } \over a}$$
C
$${{{\mu _0}} \over {4\pi }}8\sqrt 2 {{{b^2}} \over a}$$
D
$${{{\mu _0}} \over {4\pi }}{{8\sqrt 2 } \over b}$$
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