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======= ####44. A current of 2 A flows through a $2 Ω$ resistor when connected across a battery. The same battery supplies a current of $0.5 A$ when connected across a $9 Ω$ resistor. The internal resistance of the battery is

c3eec34ec6b1fad69db54a20ad4b2dca40c2aa54 (a) $0.5 Ω$

(b) $1 / 3 Ω$

(d) $1 Ω$

[2011]

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Answer:

Correct Answer: 44. (b)

Solution:

(b) Let the internal resistance of the battery be $r$ . Then the current flowing through the circuit is given by

$i = \frac{E}{R + r}$

In first case,

$2 = \frac{E}{2 + r}$

In second case,

$0.5 = \frac{E}{9 + r}$

From (1) & (2),

$4 + 2 r = 4.5 + 0.5 r$

$\Rightarrow 1.5 r = 0.5 \Rightarrow r = \frac{1}{3} Ω$ .

If $I_{1}$ be the current in a circuit with an external resistance $R_{1}$ and $I_{2}$ be the current in the circuit with external resistance $R$ , then internal resistance of cell can be find using

$r = \frac{I_{2} R_{2} - I_{1} R_{1}}{I_{1} - I_{2}}$

Current Electricity - Result Question 42

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

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Answer:

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Current Electricity - Result Question 42

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

«««< HEAD

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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