Question

A battery of emf 115V and internal resistance of 4$15.18\Omega$ is connected to a resistor. If the current in the circuit is 2A and the circuit is closed. Resistance of the resistor and terminal voltage of the battery will be

• A. 2.5, $81.15\Omega$ 6V
• B. 3.5$51.18\Omega$, 6V
• C. 2.5, $18.15\Omega$7V
• D. 3.5$r_{1}$, 7V

Answer 1

Answer: (D)

3.5$r_{1}$, 7V

Answer 2

: Given, $\varepsilon = 15V,r = 4\Omega,I = 2A$

Now, gor resistance of the resistors

$\varepsilon = Ir = V = IR$

$15 - 2 \times 4 = 2 \times R$

$15 - 8 = 2R$

$R = \frac{7}{2} = 3.5\Omega.$

Terminal voltage of battery

$V = IR = 2 \times 3.5 = 7 = V$