Current Electricity · JEE Main previous year questions

2024 66 questions

1. Q342024 · 29 Jan 2024 · Shift 1

   The deflection in moving coil galvanometer falls from 25 divisions to 5 divisions when a shunt of $24\Omega$ is applied. The resistance of galvanometer coil will be :

   1. A.$48\Omega$
   2. B.$100\Omega$
   3. C.$96\Omega$
   4. D.$12\Omega$
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   Answer: C

2. Q372024 · 29 Jan 2024 · Shift 1

   A galvanometer having coil resistance $10\Omega$ shows a full scale deflection for a current of $3\text{ mA}$. For it to measure a current of $8\text{ A}$, the value of the shunt should be:

   1. A.$3.75\times 10^{-3}\Omega$
   2. B.$3\times 10^{-3}\Omega$
   3. C.$4.85\times 10^{-3}\Omega$
   4. D.$2.75\times 10^{-3}\Omega$
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   Answer: A

3. Q552024 · 29 Jan 2024 · Shift 1· Numerical answer

   A square loop of side $10\text{ cm}$ and resistance $0.7\Omega$ is placed vertically in east-west plane. A uniform magnetic field of $0.20T$ is set up across the plane in north east direction. The magnetic field is decreased to zero in $1\text{ s}$ at a steady rate. Then, magnitude of induced emf is $\sqrt{x}\times 10^{-3}\text{ V}$. The value of $x$ is _______.

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   Answer: 2

4. Q572024 · 29 Jan 2024 · Shift 1· Numerical answer

   A $16\Omega$ wire is bent to form a square loop. A $9\text{ V}$ battery with internal resistance $1\Omega$ is connected across one of its sides. If a $4\mu \text{F}$ capacitor is connected across one of its diagonals, the energy stored by the capacitor will be $\frac{x}{2}\mu \text{J}$, where $x=$ _______.

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   Answer: 81

5. Q322024 · 29 Jan 2024 · Shift 2
   
   1. A.$2\text{ A}$
   2. B.$1.5\text{ A}$
   3. C.$1\text{ A}$
   4. D.$2.5\text{ A}$
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   Answer: C

6. Q352024 · 29 Jan 2024 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
   Show answer

   Answer: B

7. Q432024 · 29 Jan 2024 · Shift 2

   In an a.c. circuit, voltage and current are given by: $V=100\sin (100t)V$ and $I=100\sin \left(100t+\frac{\pi }{3}\right)\text{mA}$ respectively. The average power dissipated in one cycle is:

   1. A.$5\text{ W}$
   2. B.$25\text{ W}$
   3. C.$2.5\text{ W}$
   4. D.$10\text{ W}$
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   Answer: C

8. Q512024 · 29 Jan 2024 · Shift 2· Numerical answer
   
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   Answer: 30

9. Q372024 · 27 Jan 2024 · Shift 1
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: D

10. Q482024 · 27 Jan 2024 · Shift 1

    A wire of length $10\text{ cm}$ and radius $\sqrt{7}\times 10^{-4}\text{ m}$ is connected across the right gap of a meter bridge. When a resistance of $4.5\Omega$ is connected on the left gap by using a resistance box, the balance length is found to be at $60\text{ cm}$ from the left end. If the resistivity of the wire is $R\times 10^{-7}\Omega \text{m}$, then value of $R$ is :

    1. A.$63$
    2. B.$70$
    3. C.$66$
    4. D.$35$
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    Answer: C

11. Q492024 · 27 Jan 2024 · Shift 1

    A wire of resistance $R$ and length $L$ is cut into $5$ equal parts. If these parts are joined parallelly, then resultant resistance will be :

    1. A.$\frac{1}{25}R$
    2. B.$\frac{1}{5}R$
    3. C.$25\text{ R}$
    4. D.$5\text{ R}$
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    Answer: A

12. Q342024 · 27 Jan 2024 · Shift 2

    Primary side of a transformer is connected to $230\text{ V},50\text{ Hz}$ supply. Turns ratio of primary to secondary winding is $10:1$. Load resistance connected to secondary side is $46\Omega$. The power consumed in it is :

    1. A.$11.5\text{ W}$
    2. B.$12.5\text{ W}$
    3. C.$10.0\text{ W}$
    4. D.$12.0\text{ W}$
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    Answer: A

13. Q422024 · 27 Jan 2024 · Shift 2
    
    1. A.$V_1=V_2$
    2. B.$V_1\ne V_3-V_2$
    3. C.$V_1+V_2=V_3$
    4. D.$V_1+V_2>V_3$
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    Answer: C

14. Q482024 · 27 Jan 2024 · Shift 2
    
    1. A.
    2. B.
    3. C.
    4. D.
    Show answer

    Answer: A

15. Q492024 · 27 Jan 2024 · Shift 2

    A current of $200\mu \text{A}$ deflects the coil of a moving coil galvanometer through $60^{\circ }$. The current to cause deflection through $\frac{\pi }{10}\text{ radian}$ is :

    1. A.$120\mu \text{A}$
    2. B.$180\mu \text{A}$
    3. C.$30\mu \text{A}$
    4. D.$60\mu \text{A}$
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    Answer: D

16. Q502024 · 27 Jan 2024 · Shift 2

    Wheatstone bridge principle is used to measure the specific resistance ($S_1$) of given wire, having length $L$, radius $r$. If $X$ is the resistance of wire, then specific resistance is ; $S_1=X\left(\frac{\pi r^2}{L}\right)$. If the length of the wire gets doubled then the value of specific resistance will be :

    1. A.$\frac{S_1}{4}$
    2. B.$2S_1$
    3. C.$\frac{S_1}{2}$
    4. D.$S_1$
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    Answer: D