AIEEE 2012 | Magnetic Effect of Current Question 171 | Physics

A charge $$Q$$ is uniformly distributed over the surface of non-conducting disc of radius $$R.$$ The disc rotates about an axis perpendicular to its plane and passing through its center with an angular velocity $$\omega .$$ As a result of this rotation a magnetic field of induction $$B$$ is obtained at the center of the disc. If we keep both the amount of charge placed on the disc and its angular velocity to be constant and very the radius of the disc then the variation of the magnetic induction at the center of the disc will be represented by the figure :

AIEEE 2012 Physics - Magnetic Effect of Current Question 170 English Option 1

AIEEE 2012 Physics - Magnetic Effect of Current Question 170 English Option 2

AIEEE 2012

MCQ (Single Correct Answer)

-1

Proton, deuteron and alpha particle of same kinetic energy are moving in circular trajectories in a constant magnetic field. The radii of proton, denuteron and alpha particle are respectively $${r_p},{r_d}$$ and $${r_\alpha }$$. Which one of the following relation is correct?

$${r_\alpha } = {r_p} = {r_d}$$

$${r_\alpha } = {r_p} < {r_d}$$

$${r_\alpha } > {r_d} > {r_p}$$

$${r_\alpha } = {r_d} > {r_p}$$

AIEEE 2011

MCQ (Single Correct Answer)

-1

A current $$I$$ flows in an infinitely long wire with cross section in the form of a semi-circular ring of radius $$R.$$ The magnitude of the magnetic induction along its axis is:

$${{{\mu _0}I} \over {2{\pi ^2}R}}$$

$${{{\mu _0}I} \over {2\pi R}}$$

$${{{\mu _0}I} \over {4\pi R}}$$

$${{{\mu _0}I} \over {{\pi ^2}R}}$$

AIEEE 2010

MCQ (Single Correct Answer)

-1

Two long parallel wires are at a distance $$2d$$ apart. They carry steady equal currents flowing out of the plane of the paper as shown. The variation of the magnetic field $$B$$ along the line $$XX'$$ is given by