2025 Exam Questions
Q. Which of the following equations gives correct expression for the internal resistance of a cell by using potentiometer?
(A) \mathrm{r}=\mathrm{R}\left(\frac{\mathrm{V}}{\mathrm{E}}-1\right)
(B) r=R\left(1-\frac{E}{V}\right)
(C) r=R\left(1-\frac{V}{E}\right)
(D) \quad r=R\left(\frac{E}{V}-1\right)
Q. State the advantages of a potentiometer over a voltmeter.
Q. A galvanometer has a resistance of 50 \Omega and a current of 2 mA is needed for its full scale deflection. Calculate resistance required to convert it,
(i) into an ammeter of 0.5 A range.
(ii) into a voltmeter of 10 V range.
2024 Exam Questions
Q. To convert a moving coil galvanometer into an ammeter we need to connect a
(a) small resistance in parallel with it
(b) large resistance in series with it
(c) small resistance in series with it
(d) large resistance in parallel with it
Q. What is the resistance of an ideal voltmeter?
Q. A galvanometer has a resistance of 30Ω and its full scale deflection current is 20 microampere (μA). What resistance should be added to it to have a range 0-10 volt?
Q. Distinguish between an ammeter and a voltmeter. (Two points each)
2023 Exam Questions
Q. State the formula giving relation between electric field intensity and potential gradient.
Q. Explain the use of potentiometer to determine internal resistance of a cell.
Q. What is the value of resistance for an ideal voltmeter?
Q. How will you convert a moving coil galvanometer into an ammeter?
2022 Exam Questions
Q. In potentiometer experiment, the cell balances at a length of 240 cm. When the cell is shunted by a resistance of 2 Ω, the balancing length becomes 120 cm. The internal resistance of the cell is _____.
(A) 4 Ω
(B) 2 Ω
(C) 1 Ω
(D) 0.5 Ω
Q. State Kirchhoff’s laws of electrical netwrok. OR State Kirchhoffs’ laws of electricity.
Q. Define potential gradient of the potentiometer wire.
Q. Distinguish between potentiometer and voltmeter.
Q. What is shunt?
Q. Two cells of emf 4 V and 2 V having respective internal resistance of 1 Ω and 2 Ω are connected in parallel, so as to send current in the same direction through an external resistance of 5 Ω. Find the current through the external resistance.
Q. When two cells of emfs E1 and E2 are connected in series so as to assist each other, their balancing length on potentiometer wire is found to be 3.2 m. When two cells are connected is series so as to oppose each other, the balancing length is found to be 0.7 m. Compare the emfs of two cells.
