Q145 / 180 · KCET 2016 · Physics
Potential difference between \( A \) and \( B \) in the following circuit
- A\( 4 \mathrm{~V} \)
- Correct answerB\( 5.6 \mathrm{~V} \)
- C\( 2.8 \mathrm{~V} \)
- D\( 6 \mathrm{~V} \)
Solution
Current,
\( I=\frac{E}{R+r}=\frac{6 V-4 V}{8 \Omega+2 \Omega}=\frac{2 V}{10 \Omega}=0.2 A \)
Potential difference across \( 8 \Omega \) resistor is
\( V=I \times R=0.2 \times 8 \Omega=1.6 \mathrm{~V} \)
Thus, potential difference across A and B is
\( V+4=(1.6+4)=5.6 \mathrm{~V} \)
\( I=\frac{E}{R+r}=\frac{6 V-4 V}{8 \Omega+2 \Omega}=\frac{2 V}{10 \Omega}=0.2 A \)
Potential difference across \( 8 \Omega \) resistor is
\( V=I \times R=0.2 \times 8 \Omega=1.6 \mathrm{~V} \)
Thus, potential difference across A and B is
\( V+4=(1.6+4)=5.6 \mathrm{~V} \)
Hence, the correct answer is option: 'B'.