A current of 2,A flows through a 2,Omega resi | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let $\varepsilon$ be the electromotive force (emf) and $r$ be the internal resistance of the battery.According to Ohm's law for a complete circuit

Vedclass · Accepted Answer

$\frac{1}{3}\,\Omega$

Vedclass · Answer

(B) Let $\varepsilon$ be the electromotive force (emf) and $r$ be the internal resistance of the battery.According to Ohm's law for a complete circuit,the current $I$ is given by $I = \frac{\varepsilon}{R + r}$,where $R$ is the external resistance.In the first case,$I_1 = 2\,A$ and $R_1 = 2\,\Omega$:$2 = \frac{\varepsilon}{2 + r} \implies \varepsilon = 2(2 + r) = 4 + 2r$    ....$(i)$In the second case,$I_2 = 0.5\,A$ and $R_2 = 9\,\Omega$:$0.5 = \frac{\varepsilon}{9 + r} \implies \varepsilon = 0.5(9 + r) = 4.5 + 0.5r$    ....$(ii)$Equating the expressions for $\varepsilon$ from $(i)$ and $(ii)$:$4 + 2r = 4.5 + 0.5r$$2r - 0.5r = 4.5 - 4$$1.5r = 0.5$$r = \frac{0.5}{1.5} = \frac{1}{3}\,\Omega$

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

Similar Questions

In the circuit shown,the resistance of the voltmeter is $10,000 \, \Omega$ and that of the ammeter is $20 \, \Omega$. The ammeter reading is $0.10 \, A$ and the voltmeter reading is $12 \, V$. Then $R$ is equal to ............. $\Omega$.

In the figure,the current through the $3\,\Omega$ resistor is $0.8\,A$. Then,the potential drop across the $4\,\Omega$ resistor is ........... $V$.

In the figure shown,the total resistance between $A$ and $B$ is ............. $\Omega$.

In the figure shown, if the internal resistance of the battery is $1\, \Omega$, the reading of the ammeter will be ................. $A$.

When a resistance $R_1$ is connected across a cell,the current is $I_1$ and if the resistance $R_1$ is replaced by $R_2$,the current is $I_2$. Then the internal resistance of the cell is

Vedclass Test Series

Exam Paper Generator

Online Exam Module