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प्रश्न
A battery of e.m.f. 15 V and internal resistance 3 ohm is connected to two resistors of resistances 3 ohm and 6 ohm is series Find:
(a) the current through the battery
(b) the p.d. between the terminals of the battery.
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उत्तर
(a) ε = 15 V
R = 6 + 3 = 9 ohm
r = 3 ohm
I = ?
I = ε / (R + r)
I = 15 / (9 + 3) = 15/12 = 1.25 A
(b) Current (calculated in (a) part) I = 1.25 A
External Resistance R = 6 + 3 = 9 ohm
V = IR = 1.25 × 9 = 11.25 V
संबंधित प्रश्न
A cell of e.m.f ε and internal resistance r is used to send current to an external resistance R. Write expressions for
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- the current drawn from the cell.
- the p.d. across the cell.
- voltage drop inside the cell.
A cell is used to send current to an external circuit.
- How does the voltage across its terminals compare with its e.m.f.?
- Under what condition is the e.m.f. of a cell equal to its terminal voltage?
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Find:
- The reading of the ammeter,
- The potential difference across the terminals of the cells, and
- The potential difference across the 4.5 Ω resistor.
Four cells, each of e.m.f. 1.5 V and internal resistance 2.0 ohms are connected in parallel. The battery of cells is connected to an external resistance of 2.5 ohms. Calculate:
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(ii) The current flowing in the external circuit.
(iii) The drop in potential across-the terminals of the cells.
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(ii) Total e.m.f.
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(a) Calculate the total resistance across AB.
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Explain the meaning of the term internal resistance of a cell.
The diagram in Figure shows a cell of e.m.f. ε = 4 volt and internal resistance r = 2 ohm connected to an external resistance R = 8 ohm. The ammeter A measures the current in the circuit and the voltmeter V measures the terminal voltage across the cell. What will be the readings of the ammeter and voltmeter when
- the key K is open, and
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