Potential Difference and EMF of a Cell

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Potential Difference and EMF of a Cell: Overview

This Topic covers sub-topics such as Short-circuiting, Potential Difference, Electric Cell, Potential Difference across Battery Terminal in Open Circuit and, Potential Difference across Terminals of Battery Getting Discharged

Important Questions on Potential Difference and EMF of a Cell

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The reading on a high resistance voltmeter, when a cell is connected across it, is 2.0V. When the terminals of the cell are also connected to a resistance of  3 Ω  as shown in the circuit, the voltmeter reading drops to 1.5V. The internal resistance of the cell is :

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Two sources of equal emfs are connected in series. This combination is connected to an external resistance R. The internal resistances of the two sources are r1 and r2r1>r2. If the potential difference across the source of internal resistance r1 is zero then the value of R will be

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Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20 Ω. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is :

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Is emf of cell is dependent on internal resistance of cell.

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A cell of emf E and internal resistance r is connected in series with an external resistance nr . Then, the ratio of the terminal potential difference to emf is -

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In the shown circuit, what is the potential difference across A and B?

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The potential difference V across the terminals of a battery which is getting charged is always:

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The terminal potential difference V of a battery of emf E and internal resistance r which is getting charged with electric current I flowing through it is:

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A current 2 A flows through a 2Ω resistor when connected across a battery. The same battery supplied a current 0.5 A when connected across a 9Ω resistor. The internal resistance of the battery is

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A cell of emf ε and internal resistance r is connected in series with an external resistance nr then the ratio of the terminal potential difference to emf is:

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The internal resistance of a cell is the resistance of

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For a cell, the terminal potential difference is 2.2 V when circuit is open and reduces to 1.8 V when cell is connected to a resistance R=5 Ω. The internal resistance (r) of the cell is

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A storage battery of emf 8.0 V with internal resistance 0.5Ω is being charged by a 120 V DC supply using a series resistor of 15.5Ω. What is the terminal voltage of the battery during charging?

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In the circuit shown, the potential difference between A and B is:

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In the figure shown, if the diode forward voltage drop is 0.2 V, the voltage difference between A and B is

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A cell has a terminal voltage 2 V in an open circuit and the internal resistance of the given cell is 2 Ω. If 4 A of current is flowing between points P and Q in the circuit, then the potential difference between P and Q is

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First order derivation of thermos emf produced in thermos - couple with respect to temperature gives

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Two thin rings each of radius R are placed at a distance  d apart. The charges on the rings are +q and q. The potential difference between their centres will be -
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Two cells, having the same emf which are connected in series through an external resistance R. Cells have internal resistances r1 and r2r1>r2 respectively. When the circuit is closed, then the potential difference across the first cell is zero. The value of R is:

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In the shown circuit, all three capacitor are identical and have capacitance C μF each. Each resistor has resistance of R Ω. An ideal cell of emf V volts is connected as shown. Then the magnitude of potential difference across capacitor C3 in steady state is:

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