Q. A battery of $emf\ 10\ V$ and internal resistance $3\Omega$ is connected to a resistor as shown in the figure. If the current in the circuit is $0.5\ A,$ then the resistance of the resistor will be
A) $19\ \Omega$
B) $17\ \Omega$
C) $10\ \Omega$
D) $12\ \Omega$
Explanation
(b) $i = \frac{E}{R + r} \Rightarrow 0.5 = \frac{10}{R + 3} \Rightarrow 10 = 0.5R + 1.5 \Rightarrow R = 17\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.