NEET Moving Charges and Magnetism PYQ practice sheet

16 previous-year NEET Physics questions from Moving Charges and Magnetism, newest papers first. Moving Charges and Magnetism carries 18 of the Physics questions in NEET 2020 to 2026, so this is a good place to test yourself after revising the chapter. Marking: +4 correct, −1 wrong.

Practise all 16 online

1.
RE-NEET 2026
A current $I_0$ flows through a metallic circular loop of radius $r$ as shown in the figure. Resistance of the segment $ABC$ is half that of $ADC$ . Magnitude of magnetic field at the centre $O$ of the loop is : Figure: a circular loop with $A$ at the top and $C$ at the bottom (diametrically opposite); $B$ is on the left arc and $D$ on the right arc. Current $I_0$ enters at $A$ and leaves at $C$ .
- (A)
  $\frac{\mu_0 I_0}{2r}$
- (B)
  $\frac{\mu_0 I_0}{4r}$
- (C)
  $\frac{\mu_0 I_0}{2\pi r}$
- (D)
  $\frac{\mu_0 I_0}{12r}$
2.
RE-NEET 2026
Two infinitely long parallel conducting wires $A$ and $B$ carry currents $I$ and $2I$ , respectively, in the same direction. The wire $A$ has uniform mass per unit length $\lambda$ and lies on an insulated floor. The wire $B$ is kept fixed at a height $h$ above the floor. The minimum magnitude of $h$ so that the wire $A$ does not rise from the floor is: [ $g$ is the acceleration due to gravity and $\mu_0$ is the permeability of free space.]
- (A)
  $\frac{2\mu_0 I^2}{\pi\lambda g}$
- (B)
  $\frac{\mu_0 I^2}{\pi\lambda g}$
- (C)
  $\frac{\mu_0 I^2}{2\pi\lambda g}$
- (D)
  $\frac{4\mu_0 I^2}{\pi\lambda g}$
3.
NEET 2026
A 100-turn closely wound circular coil of radius 5 cm has a magnetic field of $3.14\times10^{-3}$ T at its centre. The current flowing through the coil, and the magnitude of the magnetic moment of this coil are, respectively: (Take $\mu_0=4\pi\times10^{-7}$ T m/A)
- (A)
  2 A, 4 A m $^2$
- (B)
  2 A, 10 A m $^2$
- (C)
  2.5 A, 2 A m $^2$
- (D)
  2.5 A, 20 A m $^2$
4.
NEET 2026
A galvanometer of resistance $100\ \Omega$ gives full scale deflection for a current of 1 mA. It is converted into an ammeter of range 0 - 10 A. The shunt required is:
- (A)
  $1.0\ \Omega$
- (B)
  $0.10\ \Omega$
- (C)
  $0.001\ \Omega$
- (D)
  $0.01\ \Omega$
5.
NEET 2026
The figure given below shows a long straight solid wire of circular cross-section of radius ' $a$ ' carrying steady current $I$ . The current $I$ is uniformly distributed across its cross-section. The plot which correctly represents the variation of magnetic field ( $B$ ) with distance ( $r$ ) from the axis of the conductor in the region is:
- (A)
- (B)
- (C)
- (D)
6.
NEET 2024
A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4\pi\times10^{-7}$ SI units):
- (A)
  44 mT
- (B)
  4.4 T
- (C)
  4.4 mT
- (D)
  44 T
7.
NEET 2023
A very long conducting wire is bent in a semi-circular shape from $A$ to $B$ as shown in figure. The magnetic field at point $P$ for steady current configuration is given by : Figure (described): Two long straight collinear horizontal wire segments carry current $i$ : the upper one towards the right ending at $A$ , the lower one leaving $B$ towards the left. $A$ and $B$ are joined by a semicircular arc of radius $R$ whose centre is $P$ .
- (A)
  $\dfrac{\mu_0 i}{4R}\left[1-\dfrac{2}{\pi}\right]$ pointed into the page
- (B)
  $\dfrac{\mu_0 i}{4R}$ pointed into the page
- (C)
  $\dfrac{\mu_0 i}{4R}$ pointed away from the page
- (D)
  $\dfrac{\mu_0 i}{4R}\left[1-\dfrac{2}{\pi}\right]$ pointed away from page
8.
NEET 2023
A wire carrying a current $I$ along the positive $x$ -axis has length $L$ . It is kept in a magnetic field $\vec B = (2\hat i + 3\hat j - 4\hat k)\ \mathrm{T}$ . The magnitude of the magnetic force acting on the wire is :
- (A)
  $\sqrt3\,IL$
- (B)
  $3\,IL$
- (C)
  $\sqrt5\,IL$
- (D)
  $5\,IL$
9.
NEET 2022
Given below are two statements: Statement I: Biot-Savart's law gives us the expression for the magnetic field strength of an infinitesimal current element ( $Idl$ ) of a current carrying conductor only. Statement II: Biot-Savart's law is analogous to Coulomb's inverse square law of charge $q$ , with the former being related to the field produced by a scalar source, $Idl$ while the latter being produced by a vector source, $q$ . In light of the above statements, choose the most appropriate answer from the options given below:
- (A)
  Statement I is incorrect and Statement II is correct
- (B)
  Both Statement I and Statement II are correct
- (C)
  Both Statement I and Statement II are incorrect
- (D)
  Statement I is correct and Statement II is incorrect
10.
NEET 2022
A long solenoid of radius 1 mm has 100 turns per mm. If 1 A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:
- (A)
  $6.28\times10^{-4}$ T
- (B)
  $6.28\times10^{-2}$ T
- (C)
  $12.56\times10^{-2}$ T
- (D)
  $12.56\times10^{-4}$ T
11.
NEET 2022
From Ampere's circuital law for a long straight wire of circular cross-section carrying a steady current, the variation of magnetic field in the inside and outside region of the wire is:
- (A)
  a linearly decreasing function of distance upto the boundary of the wire and then a linearly increasing one for the outside region
- (B)
  uniform and remains constant for both the regions
- (C)
  a linearly increasing function of distance upto the boundary of the wire and then linearly decreasing for the outside region
- (D)
  a linearly increasing function of distance r upto the boundary of the wire and then decreasing one with $1/r$ dependence for the outside region
12.
NEET 2021
An infinitely long straight conductor carries a current of $5\ \mathrm{A}$ as shown. An electron is moving with a speed of $10^{5}\ \mathrm{m/s}$ parallel to the conductor. The perpendicular distance between the electron and the conductor is $20\ \mathrm{cm}$ at an instant. Calculate the magnitude of the force experienced by the electron at that instant. Figure: a long straight wire PQ carries current $5\ \mathrm{A}$ from P to Q. The electron, at a perpendicular distance of $20\ \mathrm{cm}$ from the wire, moves with velocity $10^{5}\ \mathrm{m/s}$ in the same direction as the current (parallel to the wire).
- (A)
  $4\times10^{-20}\ \mathrm{N}$
- (B)
  $8\pi\times10^{-20}\ \mathrm{N}$
- (C)
  $8\times10^{-20}\ \mathrm{N}$
- (D)
  $4\pi\times10^{-20}\ \mathrm{N}$
13.
NEET 2021
A thick current carrying cable of radius $R$ carries current $I$ uniformly distributed across its cross-section. The variation of magnetic field $B(r)$ due to the cable with the distance $r$ from the axis of the cable is represented by :
- (A)
- (B)
- (C)
- (D)
14.
NEET 2021
A uniform conducting wire of length $12a$ and resistance $R$ is wound up as a current carrying coil in the shape of, (i) an equilateral triangle of side $a$ . (ii) a square of side $a$ . The magnetic dipole moments of the coil in each case respectively are :
- (A)
  $3Ia^{2}$ and $4Ia^{2}$
- (B)
  $\sqrt{3}Ia^{2}$ and $3Ia^{2}$
- (C)
  $4Ia^{2}$ and $3Ia^{2}$
- (D)
  $3Ia^{2}$ and $Ia^{2}$
15.
NEET 2021
In the product $\vec{F} = q(\vec{v}\times\vec{B}) = q\vec{v}\times(B\hat{i}+B\hat{j}+B_0\hat{k})$ . For $q = 1$ and $\vec{v} = 2\hat{i}+4\hat{j}+6\hat{k}$ and $\vec{F} = 4\hat{i}-20\hat{j}+12\hat{k}$ . What will be the complete expression for $\vec{B}$ ?
- (A)
  $-6\hat{i}-6\hat{j}-8\hat{k}$
- (B)
  $8\hat{i}+8\hat{j}-6\hat{k}$
- (C)
  $-8\hat{i}-8\hat{j}-6\hat{k}$
- (D)
  $6\hat{i}+6\hat{j}-8\hat{k}$
16.
NEET 2020
A long solenoid of $50$ cm length having $100$ turns carries a current of $2.5$ A. The magnetic field at the centre of the solenoid is : ( $\mu_0=4\pi\times10^{-7}$ T m A $^{-1}$ )
- (A)
  $6.28\times10^{-4}$ T
- (B)
  $3.14\times10^{-4}$ T
- (C)
  $6.28\times10^{-5}$ T
- (D)
  $3.14\times10^{-5}$ T

Answer key

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