Potentiometer PYQs: JEE Mains Physics

Showing 1–25 of 25 questions

1. 1. In the potentiometer, when the cell in the secondary circuit is shunted with 4 \(\Omega\) resistance, the balance is obtained at the length 120 cm of wire. Now when the same cell is shunted with 12 \(\Omega\) resistance, the balance is shifted to a length of 180 cm. The internal resistance of cell is ___________ \(\Omega\). 2026 Medium
2. 2. To compare EMF of two cells using potentiometer the balancing lengths obtained are 200 cm and 150 cm . The least count of scale is 1 cm . The percentage error in the ratio of EMFs is ___________. 2026 Medium
3. 3. To measure the internal resistance of a battery, potentiometer is used. For \(\mathrm{R}=10 \Omega\), the balance point is observed at \(\ell=500 \mathrm{~cm}\) and for \(\mathrm{R}=1 \Omega\) the balance point is observed at \(\ell=400 \mathrm{~cm}\). The internal resistance of the battery is approximately _______. 2024 Hard
4. 4. 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 \(..............\,\Omega\). 2023 Medium
5. 5. In an experiment to find \(emf\) of a cell using potentiometer, the length of null point for a cell of emf \(1.5\,V\) is found to be \(60\,cm\). If this cell is replaced by another cell of \(emf\; E\). the length-of null point increases by \(40\,cm\). The value of \(E\) is \(\frac{x}{10} V\). The value of \(x\) is \(............\) 2023 Medium
6. 6. 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: 2023 Medium
7. 7. A cell, shunted by a \(8 \; \Omega\) resistance, is balanced across a potentiometer wire of length \(3 \;  m\). The balancing length is \(2 \; m\) when the cell is shunted by \(4 \; \Omega\) resistance. The value of internal resistance of the cell will be \(\dots \; \Omega .\) 2022 Medium
8. 8. A potentiometer wire of length \(10 \,m\) and resistance\(20 \,\Omega\) is connected in series with a \(25 \,V\) battery and an external resistance \(30\, \Omega\). A cell of emf \(E\) in secondary circuit is balanced by \(250\, cm\) long potentiometer wire. The value of \(E\) (in volt) is \(\frac{x}{10}\). The value of \(x\) is....... 2022 Medium
9. 9. A potentiometer wire of length \(300\,cm\) is connected in series with a resistance \(780\,\Omega\) and a standard cell of emf \(4\,V\). A constant current flows through potentiometer wire. The length of the null point for cell of emf \(20\,mV\) is found to be \(60\,cm\). The resistance of the potentiometer wire is\(...\Omega\)
   2022 Hard
10. 10. As shown in the figure, a potentiometer wire of resistance \(20\,\Omega\) and length \(300\,cm\) is connected with resistance box (R.B.) and a standard cell of emf \(4\,V\). For a resistance ' \(R\) ' of resistance box introduced into the circuit, the null point for a cell of \(20\,mV\) is found to be \(60\,cm\). The value of ' \(R\) ' is \(.....\Omega\)
    2022 Medium
11. 11. In a potentiometer arrangement, a cell gives a balancing point at \(75\, cm\) length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells respectively is \(3: 2\), the difference in the balancing length of the potentiometer wire in above two cases will be.........\(cm .\) 2022 Medium
12. 12. In a potentiometer arrangement, a cell of emf \(1.20\, V\) gives a balance point at \(36\, cm\) length of wire. This cell is now replaced by another cell of emf \(1.80\, V\). The difference in balancing length of potentiometer wire in above conditions will be \(....cm\). 2022 Hard
13. 13. In the given circuit of potentiometer, the potential difference \(E\) across \(AB\) ( \(10\, m\) length) is larger than \(E _{1}\) and \(E _{2}\) as well. For key \(K _{1}\) (closed), the jockey is adjusted to touch the wire at point \(J_{1}\) so that there is no deflection in the galvanometer. Now the first battery \(\left( E _{1}\right)\) is replaced by second battery \(\left( E _{2}\right)\) for working by making \(K _{1}\) open and \(K _{2}\) closed. The galvanometer gives then null deflection at \(J _{2}\). The value of \(\frac{ E _{1}}{ E _{2}}\) is \(\frac{ a }{ b },\) where \(a =\) ...............
    2021 Medium
14. 14. In the given figure, there is a circuit of potentiometer of length \(A B=10 \,{m}\). The resistance per unit length is \(0.1 \,\Omega\) per \({cm}\). Across \({AB}\), a battery of emf \({E}\) and internal resistance ' \({r}^{\prime}\) is connected. The maximum value of emf measured by this potentiometer is : (In \(V\))
    2021 Medium
15. 15. In the given potentiometer circuit arrangement, the balancing length \({AC}\) is measured to be \(250\) \({cm}\). When the galvanometer connection is shifted from point \((1)\) to point \((2)\) in the given diagram, the balancing length becomes \(400\, {cm}\). The ratio of the emf of two cells, \(\frac{\varepsilon_{1}}{\varepsilon_{2}}\) is -
    2021 Hard
16. 16. the given potentiometer has its wire of resistance \(10\, \Omega\). When the sliding contact is in the middle of the potentiometer wire, the potential drop across \(2\, \Omega\) resistor is -
    2021 Hard
17. 17. A potentiometer wire \(PQ\) of \(1\,m\) length is connected to a standard cell \(E _{1}\). Another cell \(E _{2}\) of emf \(1.02\, V\) is connected with a resistance \('r'\) and switch \(S\) (as shown in figure). With switch \(S\) open, the null position is obtained at a distance of \(49\, cm\) from \(Q\). The potential gradient in the potentiometer wire is.......\(V/cm\)
    2020 Medium
18. 18. The balancing length for a cell is \(560 \;\mathrm{cm}\) in a potentiometer experiment. When an external resistance of \(10 \;\Omega\) is connected in parallel to the cell, the balancing length changes by \(60\; \mathrm{cm} .\) If the internal resistance of the cell is \(\frac{\mathrm{N}}{10} \;\Omega,\) where \(\mathrm{N}\) is an integer then value of \(\mathrm{N}\) is 2020 Medium
19. 19. The length of a potentiometer wire is \(1200\; \mathrm{cm}\) and it carries a current of \(60 \;\mathrm{mA}\). For a cell of \(emf\;5\; \mathrm{V}\) and intemal resistance of \(20\; \Omega,\) the null point on it is found to be a \(1000\; \mathrm{cm} .\) The resistance of whole wire is .............. \(\Omega\) 2020 Medium
20. 20. A potentiometer wire \(AB\) having length \(L\) and resistance \(12\, r\) is joined to a cell \(D\) of \(emf\) \(\varepsilon \) and internal resistance \(r\). A cell \(C\) having \(emf\) \(\varepsilon /2\) and internal resistance \(3r\) is connected. The length \(AJ\) at which the galvanometer as shown in figure shows no deflection is
    2019 Medium
21. 21. An ideal battery of \(4\, V\) and resistance \(R\) are connected in series in the primary circuit of a potentiometer of length \(1\, m\) and resistance \(5\,\Omega \) . The value of \(R\), to give a difference of \(5\, mV\) across \(10\, cm\) of potentiometer wire, is: ................ \(\Omega\) 2019 Medium
22. 22. In the circuit shown, a four wire potentiometer is made of a \(400\, cm\) long wire, which extends between \(A\) and \(B\). The resistance per unit length of the potentiometer wire is \(r = 0.01\, \Omega /cm\). If an ideal voltmeter is connected as shown with jockey \(J\) at \(50\, cm\) from end \(A\), the expected reading of the voltmeter will be: ............... \(V\)
    2019 Medium
23. 23. In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across \(52\ cm\) of the potentiometer wire. If the cell is shunted by a resistance of \( 5\,\Omega\), a balance is found when the cell is connected across \(40\ cm\) of the wire. Find the internal resistance of the cell ........... \(\Omega\) 2018 Medium
24. 24. A potentiometer \(PQ\) is set up to compare two resistances as shown in the figure. The ameter \(A\) in the circuit reads \(1.0\, A\) when two way key \(K_3\) is open. The balance point is at a length \(l_1\, cm\) from \(P\) when two way key \(K_3\) is plugged in between \(2\) and \(1\) , while the balance point is at a length \(l_2\, cm\) from \(P\) when key \(K_3\) is plugged in between \(3\) and \(1\) . The ratio of two resistances \(\frac{{{R_1}}}{{{R_2}}}\) is found to be
    2017 Medium
25. 25. In the experiment of calibration of voltmeter, a standard cell of \(e.m.f\,\,1.1\,volt\) is balanced against \(440\,cm\) of potential wire. The potential difference across the ends of resistance is found to balance against \(220\,cm\) of the wire. The corresponding reading of voltmeter is \(0.5\,volt.\) The error in the reading of volmeter will be .................. \(volt\) 2014 Hard

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