The magnetic moments associated with two closely wound circular coils A and B of radius r_A=10 cm and r_B=20 cm respectively are equal if: (Where N_A, I _A and N_ B , I _ B are number of turn and current of A and B

Correct answer: C. N_ A I _ A =4 N_ B I _ B The magnetic moment associated with circular coil, aligned & M=N I A & M_A=M_B & N_A I_A A_A=N_B I_B A_B & N_A I_A π(0.1)^2=N_B I_B π(0.2)^2( A=π r^2) & N_A I_A=4 N_B I_B aligned

BITSAT 2023Paper 2

Exam: BITSAT
Year: 2023
Paper: Paper 2
Subject: Physics
Chapter: Magnetic Effects of Current

BITSAT 2023 · Paper 2 · Physics · Magnetic Effects of Current

The magnetic moments associated with two closely wound circular...

The magnetic moments associated with two closely wound circular coils A and B of radius

r_A=10 \mathrm{ cm}

and

r_B=20 \mathrm{ cm}

respectively are equal if: (Where

\mathrm{N}_A,

\mathrm{I}

_A

and

\mathrm{N}_{\mathrm{B}},

\mathrm{I}

_{\mathrm{B}}

are number of turn and current of

A

and

B

respectively)

Options

A $2 \mathrm{ N}_{\mathrm{A}}$ \mathrm{I} $_{\mathrm{A}}=\mathrm{N}_{\mathrm{B}}$ \mathrm{I} $_{\mathrm{B}}$
B $\mathrm{N}_{\mathrm{A}}=2 \mathrm{ N}_{\mathrm{B}}$
C $\mathrm{N}_{\mathrm{A}}$ \mathrm{I} $_{\mathrm{A}}=4 \mathrm{ N}_{\mathrm{B}}$ \mathrm{I} $_{\mathrm{B}}$
D $4 \mathrm{ N}_{\mathrm{A}}$ \mathrm{I} $_{\mathrm{A}}=\mathrm{N}_{\mathrm{B}}$ \mathrm{I} $_{\mathrm{B}}$

Correct answer

C. $\mathrm{N}_{\mathrm{A}}$ \mathrm{I} $_{\mathrm{A}}=4 \mathrm{ N}_{\mathrm{B}}$ \mathrm{I} $_{\mathrm{B}}$

Step-by-step solution

The magnetic moment associated with circular coil,

\begin{aligned} \\ & M=N I A \\ \\ & M_A=M_B \\ \\ & \therefore N_A I_A A_A=N_B I_B A_B \\ \\ & \therefore N_A I_A \pi(0.1)^2=N_B I_B \pi(0.2)^2\left(\because A=\pi r^2\right) \\ \\ & \therefore N_A I_A=4 N_B I_B \\ \end{aligned}

Practice Magnetic Effects of Current on Quantrex Academy →

More from Magnetic Effects of Current

The straight wire A B carries a current I . The ends of the wire subtend angles θ_1 and… BITSAT 2024 A long straight wire of radius a carries a steady current 1. The current is uniformly… BITSAT 2024 The electrostatic force ( F_1) and magnetic force ( F_2) acting on a charge q moving with… BITSAT 2024 A solenoid of 1200 turns is wound uniformly in a single layer on a glass tube 2 m long… BITSAT 2023 A charge particle is moving in a uniform magnetic field (2 i +3 j ) T . If it has an… BITSAT 2023 The magnetic moment of an electron (e) revolving in an orbit around nucleus with an… BITSAT 2023 A proton moving with a velocity 3 × 10^ 5 m / s enters a magnetic field of 0.3 tesla at… BITSAT 2021 A solenoid is 2 m long and 3 cm in diameter. It has 5 layers of winding of 1000 turns… BITSAT 2021 Full Magnetic Effects of Current list All BITSAT PYQs