SATHEE: Current Electricity - Result Question 79

Current Electricity - Result Question 79

84. A battery of $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered is maximum is equal to

[2001, 1992]

(a) $0.25 Ω$

(b) $0.5 Ω$

(d) $2.0 Ω$

Show Answer

Answer:

Correct Answer: 84. (b)

Solution:

(b) Power is maximum when $r = R, R = r = 0.5 Ω$ .

If a cell of internal resistance $r$ and emf $E$ is connected to an external resistance of radius $R$ , then current given by cell, $I = \frac{E}{R + r}$

Power dissipated in external resistance (load) $P = V I = (I R) I = I^{2} R$

$\Rightarrow P = (\frac{E}{R + r})^{2} R$

when $R = r$

Power, $P = \frac{E^{2}}{4 r}$ (Maximum)

Current Electricity - Result Question 79

84. A battery of $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered is maximum is equal to

Answer:

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Current Electricity - Result Question 79

84. A battery of 10V and internal resistance 0.5Ω is connected across a variable resistance R. The value of R for which the power delivered is maximum is equal to

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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84. A battery of $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered is maximum is equal to