Current Electricity · JEE Main previous year questions

2023 60 questions

1. Q442023 · 6 Apr 2023 · Shift 1

   Two resistances are given as ${\text{R}}_1=(10\pm 0.5)\Omega$ and ${\text{R}}_2=(15\pm 0.5)\Omega$. The percentage error in the measurement of equivalent resistance when they are connected in parallel is -

   1. A.2.33
   2. B.5.33
   3. C.4.33
   4. D.6.33
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   Answer: C

2. Q572023 · 6 Apr 2023 · Shift 1· Numerical answer

   The length of a metallic wire is increased by $20\%$ and its area of cross section is reduced by $4\%$. The percentage change in resistance of the metallic wire is ________.

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   Answer: 25

3. Q392023 · 6 Apr 2023 · Shift 2
   
   1. A.$0.2\mathrm{A}$
   2. B.$0.6\mathrm{A}$
   3. C.$0.4\mathrm{A}$
   4. D.$1.0\mathrm{A}$
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   Answer: C

4. Q442023 · 6 Apr 2023 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
   Show answer

   Answer: C

5. Q552023 · 6 Apr 2023 · Shift 2· Numerical answer
   
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   Answer: 20

6. Q362023 · 1 Feb 2023 · Shift 1
   
   1. A.$21\text{ R}$
   2. B.$\frac{8}{3}\text{ R}$
   3. C.$11\frac{2}{3}\text{ R}$
   4. D.$14\text{ R}$
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   Answer: B

7. Q402023 · 1 Feb 2023 · Shift 1

   A child stands on the edge of the cliff $10\text{ m}$ above the ground and throws a stone horizontally with an initial speed of $5{\text{ ms}}^{-1}$. Neglecting the air resistance, the speed with which the stone hits the ground will be ________ ${\text{ms}}^{-1}$ (given, $g=10{\text{ ms}}^{-2}$).

   1. A.20
   2. B.25
   3. C.30
   4. D.15
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   Answer: D

8. Q602023 · 1 Feb 2023 · Shift 1· Numerical answer

   In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf $1.5\text{ V}$ is found to be $60\text{ cm}$. If this cell is replaced by another cell of emf E, the length-of null point increases by $40\text{ cm}$. The value of $E$ is $\frac{x}{10}\text{ V}$. The value of $x$ is ________.

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   Answer: 25

9. Q342023 · 31 Jan 2023 · Shift 1

   The effect of increase in temperature on the number of electrons in conduction band ($n_{\mathrm{e}}$) and resistance of a semiconductor will be as:

   1. A.$n_{\mathrm{e}}$ decreases, resistance increases
   2. B.Both $n_{\mathrm{e}}$ and resistance increase
   3. C.$n_{\mathrm{e}}$ increases, resistance decreases
   4. D.Both $n_{\mathrm{e}}$ and resistance decrease
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   Answer: C

10. Q362023 · 31 Jan 2023 · Shift 1

    The drift velocity of electrons for a conductor connected in an electrical circuit is $V_{\mathrm{d}}$. The conductor is now replaced by another conductor with same material and same length but double the area of cross section. The applied voltage remains same. The new drift velocity of electrons will be

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

11. Q592023 · 31 Jan 2023 · Shift 1· Numerical answer

    Two identical cells, when connected either in parallel or in series gives same current in an external resistance $5\Omega$. The internal resistance of each cell will be ___________ $\Omega$.

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    Answer: 5

12. Q602023 · 31 Jan 2023 · Shift 1· Numerical answer

    An inductor of $0.5\text{ mH}$, a capacitor of $20\mu \mathrm{F}$ and resistance of $20\Omega$ are connected in series with a $220\text{ V}$ ac source. If the current is in phase with the emf, the amplitude of current of the circuit is $\sqrt{x}\text{ A}$. The value of $x$ is ___________

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    Answer: 242

13. Q352023 · 31 Jan 2023 · Shift 2

    The number of turns of the coil of a moving coil galvanometer is increased in order to increase current sensitivity by $50\%$. The percentage change in voltage sensitivity of the galvanometer will be :

    1. A.$0\%$
    2. B.$75\%$
    3. C.$100\%$
    4. D.$50\%$
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    Answer: A

14. Q372023 · 31 Jan 2023 · Shift 2

    The $\mathrm{H}$ amount of thermal energy is developed by a resistor in $10\text{ s}$ when a current of $4\text{ A}$ is passed through it. If the current is increased to $16\text{ A}$, the thermal energy developed by the resistor in $10\text{ s}$ will be :

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

15. Q562023 · 31 Jan 2023 · Shift 2· Numerical answer
    
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    Answer: 1

16. Q312023 · 30 Jan 2023 · Shift 1
    
    1. A.$1\mathrm{V}$
    2. B.$\frac{1}{10}\mathrm{V}$
    3. C.$10\mathrm{V}$
    4. D.$100\mathrm{V}$
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    Answer: C

17. Q362023 · 30 Jan 2023 · Shift 1
    
    1. A.
    2. B.
    3. C.
    4. D.
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    Answer: D

18. Q512023 · 30 Jan 2023 · Shift 1· Numerical answer
    
    Show answer

    Answer: 1.5

19. Q472023 · 29 Jan 2023 · Shift 1

    Ratio of thermal energy released in two resistors R and 3R connected in parallel in an electric circuit is :

    1. A.1 : 1
    2. B.1 : 27
    3. C.1 : 3
    4. D.3 : 1
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    Answer: D

20. Q532023 · 29 Jan 2023 · Shift 1· Numerical answer

    In a metre bridge experiment the balance point is obtained if the gaps are closed by $2\Omega$ and $3\Omega$. A shunt of X $\Omega$ is added to $3\Omega$ resistor to shift the balancing point by 22.5 cm. The value of X is ____.

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    Answer: 2

21. Q342023 · 29 Jan 2023 · Shift 2

    A square loop of area $25\mathrm{c}{\mathrm{m}}^2$ has a resistance of $10\Omega$. The loop is placed in uniform magnetic field of magnitude 40.0 T. The plane of loop is perpendicular to the magnetic field. The work done in pulling the loop out of the magnetic field slowly and uniformly in 1.0 sec, will be

    1. A.$1.0\times 10^{-3}\mathrm{J}$
    2. B.$5\times 10^{-3}\mathrm{J}$
    3. C.$2.5\times 10^{-3}\mathrm{J}$
    4. D.$1.0\times 10^{-4}\mathrm{J}$
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    Answer: A

22. Q482023 · 29 Jan 2023 · Shift 2

    With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is (A) directly proportional to the length of the potentiometer wire (B) directly proportional to the potential gradient of the wire (C) inversely proportional to the potential gradient of the wire (D) inversely proportional to the length of the potentiometer wire Choose the correct option for the above statements :

    1. A.A only
    2. B.B and D only
    3. C.A and C only
    4. D.C only
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    Answer: C

23. Q592023 · 29 Jan 2023 · Shift 2· Numerical answer

    When two resistance ${\mathrm{R}}_1$ and ${\mathrm{R}}_2$ connected in series and introduced into the left gap of a meter bridge and a resistance of $10\Omega$ is introduced into the right gap, a null point is found at 60 cm from left side. When ${\mathrm{R}}_1$ and ${\mathrm{R}}_2$ are connected in parallel and introduced into the left gap, a resistance of $3\Omega$ is introduced into the right gap to get null point at 40 cm from left end. The product of ${\mathrm{R}}_1{\mathrm{R}}_2$ is __________${\Omega }^2$

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    Answer: 30

24. Q602023 · 29 Jan 2023 · Shift 2· Numerical answer

    A null point is found at 200 cm in potentiometer when cell in secondary circuit is shunted by $5\Omega$. When a resistance of $15\Omega$ is used for shunting, null point moves to 300 cm. The internal resistance of the cell is __________$\Omega$.

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    Answer: 5

25. Q412023 · 25 Jan 2023 · Shift 1

    A uniform metallic wire carries a current 2 A, when 3.4 V battery is connected across it. The mass of uniform metallic wire is $8.92\times 10^{-3}\mathrm{kg}$, density is $8.92\times 10^{3}kg/{\mathrm{m}}^3$ and resistivity is $1.7\times 10^{-8}\Omega \text{-}\mathrm{m}$. The length of wire is :

    1. A.$l=100\mathrm{m}$
    2. B.$l=6.8\mathrm{m}$
    3. C.$l=5\mathrm{m}$
    4. D.$l=10\mathrm{m}$
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    Answer: D