Magnetic Effects of Current & Magnetism · JEE Main previous year questions

2026 19 questions

1. Q402026 · 8 Apr 2026 · Shift 2

   A $30\mathrm{cm}$ long solenoid has 10 turns per cm and area of $5\mathrm{c}{\mathrm{m}}^2$. The current through the solenoid coil varies from $2\mathrm{A}$ to $4\mathrm{A}$ in $3.14\mathrm{s}$. The e.m.f. induced in the coil is $\alpha \times 10^{-5}\mathrm{V}$. The value $\alpha$ is ____ .

   1. A.$60$
   2. B.$12$
   3. C.$120$
   4. D.$34$
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   Answer: B

2. Q482026 · 8 Apr 2026 · Shift 2· Numerical answer

   A $5\mathrm{mg}$ particle carrying a charge of $5\pi \times 10^{-6}\mathrm{C}$ is moving with velocity of $\left(3\hat{i}+2\hat{k}\right)\times 10^{-2}m/s$ in a region having magnetic field $\vec{B}=0.1\hat{k}Wb/{\mathrm{m}}^2$. It moves a distance of $\alpha \mathrm{meter}$ along $\hat{k}$ when it completes 5 revolutions. The value of $\alpha$ is ____ .

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   Answer: 2

3. Q382026 · 6 Apr 2026 · Shift 2

   A current of $30\text{ A}$ each flows in opposite directions in two conducting wires, placed parallel to each other at a distance of $8\text{ cm}$. The magnetic field at the mid point between the two wires is ________ $\mu \text{T}$. $\left(\frac{{\mu }_0}{4\pi }=10^{-7}{\text{ N/A}}^2\right)$

   1. A.$30$
   2. B.$300$
   3. C.$150$
   4. D.$0.0$
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   Answer: B

4. Q392026 · 6 Apr 2026 · Shift 2

   A square loop of side $2\text{ cm}$ is placed in a time varying magnetic field with magnitude as $B=0.4\sin (300t)\text{ Tesla}$. The normal to the plane of loop makes an angle of $60^{\circ }$ with the field. The maximum induced emf produced in the loop is ________ $\text{mV}$.

   1. A.$12$
   2. B.$18$
   3. C.$21$
   4. D.$24$
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   Answer: D

5. Q492026 · 5 Apr 2026 · Shift 1· Numerical answer

   The charged particle moving in a uniform magnetic field of $\left(3\hat{i}+2\hat{j}\right)\mathrm{T}$ has an acceleration $\left(4\hat{i}-\frac{x}{2}\hat{j}\right)m/{\mathrm{s}}^2$. The value of $x$ is

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   Answer: 12

6. Q412026 · 4 Apr 2026 · Shift 1

   An insulated wire is wound so that it forms a flat coil with $N=200\text{ turns}$. The radius of the innermost turn is $r_1=3\text{ cm}$, and of the outermost turn $r_2=6\text{ cm}$. If $20\text{ mA}$ current flows in it then the magnetic moment will be $\alpha \times 10^{-2}\text{ A}\cdot {\text{m}}^2$. The value of $\alpha$ is ________.

   1. A.4.4
   2. B.2.64
   3. C.3.25
   4. D.1.2
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   Answer: B

7. Q392026 · 4 Apr 2026 · Shift 2

   A solenoid has a core made of material with relative permeability $400$. The magnetic field produced in the interior of solenoid is $1.0\mathrm{T}$. The magnetic intensity in SI units is $\alpha \times 10^5$. The value of $\alpha$ is ____. (Free space permeability ${\mu }_0=4\pi \times 10^{-7}\mathrm{SI}\mathrm{units}$.)

   1. A.$\frac{25}{\pi }$
   2. B.$\frac{1}{16\pi }$
   3. C.$\frac{1}{\pi }$
   4. D.$\frac{1}{4\pi }$
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   Answer: B

8. Q482026 · 4 Apr 2026 · Shift 2· Numerical answer
   
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   Answer: 12

9. Q382026 · 2 Apr 2026 · Shift 1

   When a coil is placed in a time dependent magnetic field the power dissipated in it is $P$. The number of turns, area of the coil and radius of the coil wire are $N$, $A$ and $r$ respectively. For a second coils number of turns, area of the coil and radius of the coil wire are $2N$, $2A$ and $3r$ respectively. When the first coil is replaced with second coil the power dissipated in it is $\sqrt{2}\alpha P$. The value of $\alpha$ is ____.

   1. A.36
   2. B.$128\sqrt{2}$
   3. C.16
   4. D.64
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   Answer: A

10. Q392026 · 2 Apr 2026 · Shift 1
    
    1. A.$\frac{2+\pi }{1+\pi }$
    2. B.$\frac{1+\pi }{1-\pi }$
    3. C.$\frac{2+\pi }{1-\pi }$
    4. D.$\frac{1+\pi }{2-\pi }$
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    Answer: A

11. Q482026 · 2 Apr 2026 · Shift 1· Numerical answer

    $1\mu \mathrm{C}$ charge moving with velocity $\vec{v}=\left(\hat{i}-2\hat{j}+3\hat{k}\right)m/s$ in the region of magnetic field $\vec{\mathrm{B}}=\left(2\hat{i}+3\hat{j}-5\hat{k}\right)\mathrm{T}$. The magnitude of force acting on it is $\sqrt{\alpha }\times 10^{-6}\mathrm{N}$. The value of $\alpha$ is ____.

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    Answer: 171

12. Q342026 · 28 Jan 2026 · Shift 1

    The magnetic field at the centre of a current carrying circular loop of radius $R$ is $16\mu \mathrm{T}$. The magnetic field at a distance $x=\sqrt{3}R$ on its axis from the centre is ____ $\mu \mathrm{T}$.

    1. A.8
    2. B.2
    3. C.4
    4. D.$2\sqrt{2}$
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    Answer: B

13. Q292026 · 28 Jan 2026 · Shift 2

    A long cylindrical conductor with large cross section carries an electric current distributed uniformly over its cross-section. Magnetic field due to this current is: A. maximum at either ends of the conductor and minimum at the midpoint B. maximum at the axis of the conductor C. minimum at the surface of the conductor D. minimum at the axis of the conductor E. same at all points in the cross-section of the conductor Choose the correct answer from the options given below:

    1. A.B, C Only
    2. B.E Only
    3. C.A, D Only
    4. D.D Only
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    Answer: D

14. Q302026 · 23 Jan 2026 · Shift 1

    A 20 m long uniform copper wire held horizontally is allowed to fall under the gravity ($g=10{\text{ m/s}}^2$) through a uniform horizontal magnetic field of 0.5 Gauss perpendicular to the length of the wire. The induced EMF across the wire when it travels a vertical distance of 200 m is ____ mV .

    1. A.$200\sqrt{10}$
    2. B.$0.2\sqrt{10}$
    3. C.$20\sqrt{10}$
    4. D.$2\sqrt{10}$
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    Answer: C

15. Q302026 · 23 Jan 2026 · Shift 2

    A circular loop of radius $7\text{ cm}$ is placed in uniform magnetic field of $0.2\text{ T}$ directed perpendicular to plane of loop. The loop is converted into a square loop in $0.5\text{ s}$. The EMF induced in the loop is _____ mV.

    1. A.13.2
    2. B.6.6
    3. C.1.32
    4. D.8.25
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    Answer: C

16. Q412026 · 23 Jan 2026 · Shift 2

    The current passing through a conducting loop in the form of equilateral triangle of side $4\sqrt{3}\text{ cm}$ is 2 A . The magnetic field at its centroid is $\alpha \times 10^{-5}\text{ T}$. The value of $\alpha$ is _____. (Given : ${\mu }_0=4\pi \times 10^{-7}\text{ SI units}$)

    1. A.$3\sqrt{3}$
    2. B.$2\sqrt{3}$
    3. C.$\sqrt{3}$
    4. D.$\frac{\sqrt{3}}{2}$
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    Answer: A

17. Q262026 · 21 Jan 2026 · Shift 1

    A conducting circular loop of area $1.0{\mathrm{m}}^2$ is placed perpendicular to a magnetic field which varies as $B=\sin (100t)\mathrm{Tesla}$. If the resistance of the loop is $100\Omega$, then the average thermal energy dissipated in the loop in one period is ____ J.

    1. A.${\pi }^2$
    2. B.$\frac{\pi }{2}$
    3. C.$\pi$
    4. D.$2\pi$
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    Answer: C

18. Q412026 · 21 Jan 2026 · Shift 1

    A current carrying solenoid is placed vertically and a particle of mass $m$ with charge $Q$ is released from rest. The particle moves along the axis of solenoid. If $g$ is acceleration due to gravity then the acceleration (a) of the charged particle will satisfy :

    1. A.$a>g$
    2. B.$a=0$
    3. C.$0<a<g$
    4. D.$a=g$
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    Answer: D

19. Q362026 · 21 Jan 2026 · Shift 2
    
    1. A.$-\frac{{\mu }_0}{2\pi }\frac{I}{r}(\pi +1)\hat{i}$
    2. B.$-\frac{{\mu }_0}{2\pi }\frac{I}{r}(\pi -1)\hat{i}$
    3. C.$\frac{{\mu }_0}{2\pi }\frac{I}{r}(\pi +1)\hat{i}$
    4. D.$\frac{{\mu }_0}{2\pi }\frac{I}{r}(\pi -1)\hat{i}$
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    Answer: B