1
AP EAPCET 2025 - 22nd May Evening Shift
MCQ (Single Correct Answer)
+1
-0

In a wire of radius 1 mm a steady current of 2 A uniformly distributed across the cross-section of the wire is flowing. Then the magnetic field at a point 0.25 mm from the centre of the wire is

A

$100 \mu \mathrm{~T}$

B

$200 \mu \mathrm{~T}$

C

$300 \mu \mathrm{~T}$

D

$400 \mu \mathrm{~T}$

2
AP EAPCET 2025 - 22nd May Evening Shift
MCQ (Single Correct Answer)
+1
-0

The magnetic field at the centre of a current carrying circular coil of radius $R$ is $B_c$ and the magnetic field at a point on its axis at a distance $R$ from its centre is $B_a$. The value of $\frac{B_c}{B_a}$ is

A

$\sqrt{2}$

B

$\frac{1}{2 \sqrt{2}}$

C

$2 \sqrt{2}$

D

$\frac{1}{\sqrt{2}}$

3
AP EAPCET 2025 - 22nd May Evening Shift
MCQ (Single Correct Answer)
+1
-0

A short bar magnet of magnetic moment $10^4 \mathrm{JT}^{-1}$ is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from the direction parallel to a horizontal magnetic field of $4 \times 10^{-5} \mathrm{~T}$ to a direction $60^{\circ}$ to the direction of the field is

A

0.2 J

B

2.6 J

C

0.4 J

D

6.2 J

4
AP EAPCET 2025 - 22nd May Evening Shift
MCQ (Single Correct Answer)
+1
-0

A metallic disc of radius 0.3 m is rotating with a constant angular speed of $60 \mathrm{rad} \mathrm{s}^{-1}$ in a plane perpendicular to a uniform magnetic field of $5 \times 10^{-2} \mathrm{~T}$. The emf induced between a point on the rim and centre of the disc is

A

0.06 V

B

0.612 V

C

1.35 V

D

0.135 V